The $40, Temp-Sensing Fan Mod

[95ttoplt1]

Hey guys after looking at the fan mods here and taking some hints, I came up with my own design. I didn't like the idea of having to manualy turn them on and off. I'm lazy.

I tested this on my SRT-8, with 180 T-stat, the highest temps I saw, were 190 at the end of a WOT blast, within 1/8 mile the temps were right back to 183.

I have mine set fully counter clock wise, and they come one by themselves at 180, key on or off.

Tools needed:
13mm socket and ratchet
Electrical crimp pliers
Soldering iron
Solder
Small flat blade screw driver
Drill and 3/8 bit
Something to cut metal bracket(tin snips, hacksaw ect..)

Total cost is around 40 dollars, the only thing you need is the kit I listed and a extra relay(optional, you can use the stock relay.


Anyway I found this little control at Summit for 24.99 plus 10 bucks handling.

Its made by Flex-a-lite and is partnumber 31147



http://i20.photobucket.com/albums/b207/95ttoplt1/PICT0001.jpg



Here is what comes in the kit.

http://i20.photobucket.com/albums/b207/95ttoplt1/100_1140.jpg

There is a length of wire, 2 spade connectors, 1 ring connector, 3 sheet metal scews, 2 machine screws, 2 flat washers, insulated cover, temp control, bracket, butt connector, knob for temp control.

The first order of bussiness is to modify the bracket for use on our cars. For this we need to cut off the side with the three small holes. Shown here.

http://i20.photobucket.com/albums/b207/95ttoplt1/100_1143.jpg

Next you need to drill a 3/8 hole into this vertical part where the pen is pointing, as close to the top as you can, within reason.

http://i20.photobucket.com/albums/b207/95ttoplt1/100_1144.jpg

Then you can mount the bracket, I used the passenger side hood latch bolt to mount this. It stays very hidden and is easily accessed to do adjustments.

You can get to this bolt by removing the two plastic trim pieces in front of the core support. I pulled mine up from the ends like this.

http://i20.photobucket.com/albums/b207/95ttoplt1/100_1148.jpg

http://i20.photobucket.com/albums/b207/95ttoplt1/100_1149.jpg

This gives you access to this bolt, which we will mount the backet to.

http://i20.photobucket.com/albums/b207/95ttoplt1/100_1151.jpg

Remove this bolt with a 13mm socket and ratchet., Then insert the bolt into the bracket like so.

http://i20.photobucket.com/albums/b207/95ttoplt1/PICT0028.jpg

Then install the bolt into its original hole. Like so.

http://i20.photobucket.com/albums/b207/95ttoplt1/PICT0030.jpg


Next mount up the temp control. Starting with the rear screw.

http://i20.photobucket.com/albums/b207/95ttoplt1/PICT0032.jpg


Then you can run the temp probe. There are 2 ways to do this. You can insert it into the fins of the radiator(like I did) or you can losen a hose clamp and slide the temp probe between the hose and radiator neck. Just be sure not to kink the probes wire. Here is how I mounted mine. It is mounted next to the inlet to the radiator. It was hard to get in but it is crucial to get in as far as you can. Mine is about 1/4 farther in than in this picture.

http://i20.photobucket.com/albums/b207/95ttoplt1/PICT0036.jpg


Next we start the wiring.

We will need to modify or replace the gray relay shown here, notice the stock relays are black

http://i20.photobucket.com/albums/b207/95ttoplt1/PICT0041.jpg

I used a version of the Jaaked Relay found here http://ca.geocities.com/srt8_@rogers.com/main.htm

But instead of the factory relay I used a Bosch relay pictured here

http://i20.photobucket.com/albums/b207/95ttoplt1/100_1158.jpg

I actually broke my stocker so I looked for something easier and these are the ticket. I shake too bad to solder fine parts, these bosch relays were easier to solder as the parts we bigger,the parts that needed to be soldered are a bit more sustantial as well.

You can follow the directions Jaak gives to remove the cover on the relay. The bosch are easier to disassemble than the stockers as well. Make sure to mark the cover before removing, it will only go on one way.

Then you will need to seperate the two pieces that are "welded" together in this pic. I used a small pair of side cutters and pinched the pieces in two.

http://i20.photobucket.com/albums/b207/95ttoplt1/100_1175.jpg

Next bend the top tab up and the bottom tab down. Then attach the diode just as shown is Jaak's pictures, with the silver line toward the bottom of the relay. and attach the wire on top and drill the hole just as Jaak has shown.

The wiring is super simple. The wire from the relay goes to either pin on the temp control. Attach it with one of the spade termanals provided in the kit.

The other pin on the temp control simply needs to be grounded. I grounded mine to the horn mounting nut(13mm)using the ring termanal provided in the kit. When finished it should look like this.

http://i20.photobucket.com/albums/b207/95ttoplt1/PICT0040.jpg

[95ttoplt1]

Next reinstall the front trim pieces

http://i20.photobucket.com/albums/b207/95ttoplt1/PICT0037.jpg


and enjoy the final product, all hidden, automatic, and adjustable.

[MagnumFreak]

great write up, moved into the knowledgebase.

[95ttoplt1]

Thanks, In the next couple of days I am going to make a dyno switch that will install in the same location.

It would just conect the two termanals on the Temp control when on, thus making the fans run. This would be used in a hood up condition on the dyno or between rounds at the track.

[1fastsedan]

I had the same idea, but haven't gotten around to installing it. I'm glad your works so well, now I'm definitely doing it. Thanks for the great write-up and all the pics.

[jay2puff]

:thumbs_u: great write-up thanks

[Rev.Hammer]

Very nice and neat! You did famously on this, Thank you!

[Cam]

Nice job!!. Beers and Cheers to you.

[nick_danger]

Awesome! Gee, an automatic fan mod... who-da thunk? Nice write up! BEANS!

[Hemi31]

While I agree with the idae I would use a sender that screws into the T-Stat housing or head.The Temp will be more accurate and you won't risk damaging the radiator with the probe.Just my opinion though.......great job!

[Becker]

Nice mod. And my mod list keeps growning.

[Token]

Did you solder in a 680ohm resistor between pin 85 & 86 on the Bosch relay? The factory relay has the resistor in place and without one you're likely to throw a code.

[95ttoplt1]

The relays I bought already have this resistor in place :), I have driven around with these in and no codes

http://i20.photobucket.com/albums/b207/95ttoplt1/100B1161.jpg

Hemi 31, I agree that you would get a more accurate engine temp, from my tests I don't think there would be any gain. My stat opens at about 179-181, reading this temp in the head wouldn't do any good IMO as the over temp(180+) coolant isn't in the radiator yet where the fans are. I have seen the probes in the fins like I have it on many cars before and never seen a problem. I agree with your concern though.

[Fast56k]

Might want to check the relay after some use. I bought an "auto" relay that seemed heavy enough from Radio Shack. I checked it after a day, and it had just started to cave in on one corner from the heat. The inside of that box and those relays get hot. I decided on the manual switch approach. Here is a picture of my switch placement in case someone is interested.

http://www.chargerforums.com/forums/showthread.php?t=24287

C.

Silver 06 SRT-8

[jaak]

Good write up. Been talking about it for ages, glad to see someone actually did it!

Using the OEM sensor would be a good alternate as well, as a simple comparater circuit could be used, or even two, to select hi/low. But for most people this is the easiest way to do it. Just make sure you wire it to a hood switch that only grounds when the hood is closed.

Sure would suck to injure your local Chrysler Tech when he works on your car and the fans start up on their own.

[Token]

The relays I bought already have this resistor in place :), I have driven around with these in and no codesExcellent!!

[95ttoplt1]

Good write up. Been talking about it for ages, glad to see someone actually did it!

Using the OEM sensor would be a good alternate as well, as a simple comparater circuit could be used, or even two, to select hi/low. But for most people this is the easiest way to do it. Just make sure you wire it to a hood switch that only grounds when the hood is closed.

Sure would suck to injure your local Chrysler Tech when he works on your car and the fans start up on their own.


Good point Jaak, I just haven't got to this yet. I have the switch, just need to wire it. I think I will just pull one of the wires off when taking it in.

[FloridaRT]

Thanks again for a good write up, but I have 2 questions.

1. Where did you buy the relay? Cost?

2. Can you show us a photo of the relay AFTER you modified it? So we can see how it is supposed to look like when all done.

Bob

[95ttoplt1]

Yep as soon as the wife gets home I will do just that.
I bought the relay at a "Bosch" service center. I am in germany though. These relays cost me 9 euros a piece, about 13 bucks, but stuff for cars is seriously over priced here. I think you could get these in the US for about 3-5 dollars.

The part number for the relay should be the same and any parts house should be able to cross it.

[95ttoplt1]

Ok here are the pics or the Jaaked Bosch Relay.

http://i20.photobucket.com/albums/b207/95ttoplt1/101_1188.jpg

I started by spliting the two weled pieces and then soldered the wire to the top tab. The I soldered the bottom end on the diode, and the soldered the top diode lead to the wire that was installed earlier.

A couple more pictures. If you need anymore picture just ask.

I also checked the relay just after it was running and it was warm but not too hot to handle. I tore it apart to take the pictures and inspected the contacts and the guts of the relay. Everything looks good with no over heating.

http://i20.photobucket.com/albums/b207/95ttoplt1/101_1191.jpg


http://i20.photobucket.com/albums/b207/95ttoplt1/101_1189.jpg

http://i20.photobucket.com/albums/b207/95ttoplt1/101_1178.jpg

[FloridaRT]

So where does one find the Bosch relay? What does it cost? Part number?

Thanks

Bob

[95ttoplt1]

Any reliable parts house should be able to get them or cross reference them to another brand using the Bosch number.

The Bosch part number is 0332209159

its a 12v 20/30A

I got mine at "Bosch", but I live in germany. Many, many ,many Bosch relays are sold in America, that actually what I grew up knowing them as, there are many different model though. If you take yours to a knowledgable part house or electronics store you should have no problem.

I paid 9euro(13 USD) but that is way over priced as cars part are in germany. I remeber getting them at Napa for about 3-5 bucks.

[FloridaRT]

I found many Bosch relays online at several parts places, no one seems to carry the 0332209159...............oh well.

Prices run about $11.43 for the other Bosch relays.

Any chance you can find out what car the relay was listed for?

Stores here list the relays by car model, makes it hard to find the right relay.

Bob

[FloridaRT]

I did some more searching on the internet, here is what I found.

This Bosch realy is used on Saab's 90-98 as a multi-use relay, used for many things, i.e. ABS relay, cooling fan, a/c comp., power seat, FI system, headlights, etc.

No one seems to carry 0332209159 in the states, I did find 2 used ones for sale in the U.K.

Did find new relay (0332204109) in the U.S. for sale, same relay?

The search goes on........................

Bob

[95ttoplt1]

Hmm, I will look around and see what I can find

I will take that number to Bosch tommor if I can walk, and see what it is. They have all the spec in a book I can look at.

[95ttoplt1]

I found them here

http://order.waytekwire.com/CGI-BIN/LANSAWEB?WEBEVENT+L0C82A9754D39860049F3041+M37+ENG

They are 3.51 each, but you have to order 2. I would anyway that way you have a spare incase you screw up soldering.

Hope this helps.

If you really want one and this doesn't work for you I could mail you one but it would be cost prohibitive I would think. About 20 for one shipped.

[Token]

I found them here

http://order.waytekwire.com/CGI-BIN/LANSAWEB?WEBEVENT+L0C82A9754D39860049F3041+M37+ENG

They are 3.51 each, but you have to order 2. I would anyway that way you have a spare incase you screw up soldering.

Hope this helps.

If you really want one and this doesn't work for you I could mail you one but it would be cost prohibitive I would think. About 20 for one shipped.
I clickey da linkey, da linkey no workie.

[95ttoplt1]

Oh I'm sorry, I am a little looped on pain meds right now, I clicked it when I posted it, and then fell asleep before I fixed it.

The web site wont let me link that page, so here are the instructions on how to get there.

www.waytekwire.com (http://www.waytekwire.com)

Click on "products" top left

Brings up a new page, scrool down to the bottom left, in "catagorys", select "relays"

This brings up a new page with sub-catagorys, select "standard"

It brings up a page of relays and its the second from the bottom.

their item number is 75114.

You have to order 2, as they are a wholesale outlet and have a minimum of $5 per line item. Also they charge $5 for handleing. So 2 relays would cost you about 15 bucks. About what I paid for 1 over here with out shipping and handling.

[FloridaRT]

Thanks for the information............................

Bob

[95ttoplt1]

A little update.

Since this mod runs the fans in series, if one fan is unglugged you will have no fans with this mod, until the computer hicks on the high fan.

I have a bad fan and we are waiting on a new one to come in. In the mean time I have the bad one unplugged and it works as though I have no fan mod.

Hey Bob please let us know when you get a relay in hand.

[tommyzdesign]

what exactly does this do , is this essentially the same as the gsm fan mod ? basically it makes your cooling fans run more ?

sorry for all the ? , but im a exterior guy trying to learn more interior.

thanks
tz

[95ttoplt1]

It senses the temp in the radiator and turns the fans on when the temps reach a certain point.

In stock configuration the fans are controlled by the PCM and turn on at approximatley 225.

With a cooler T-stat in place, you will open the T stat and allow the water to flow through the radiator at a cooler temp, but with no air flow the temp will still climb back to the stock temps eventually.

Normally you can reprogramm the PCM to turn the fans on earlier. But no one has figured this out yet.

So this Mod has its own temp sensor and then "Hi-Jaak's" the factory relay circuit. While hiding its doings from the PCM so no codes are set.

This enables the cooling system to operate in a coordnated effort, and gives an ideal operating temp of about 180-190 for better performance.

This mod is also easily removable when the programming becomes availible.

Hope that answers your question.

[FloridaRT]

A little update.

Since this mod runs the fans in series, if one fan is unglugged you will have no fans with this mod, until the computer hicks on the high fan.

I have a bad fan and we are waiting on a new one to come in. In the mean time I have the bad one unplugged and it works as though I have no fan mod.

Hey Bob please let us know when you get a relay in hand.

I just ordered my relays (2) from Waytek today, will have to order the adj. temp control from Summit, then buy the diode from Radio Shack........

Thanks again for all the information.

Bob

[95ttoplt1]

No problem, please post your thoughts after install and catch the things I missed :)

[FloridaRT]

Placed my order at Summit, also got some new lug nuts...............Gorilla.

Bob

[95ttoplt1]

I bet you got a better deal than me. I get shipping after the fact. My international shipping was 23 bucks :(

[FloridaRT]

Well, all the parts are on their way to me, just have to visit Radio Shack today and buy the diode.

Radio Shack part#276-1101..........less than a $1 each, will buy 2, since I ordered 2 relays.

Diode # 1N4001 30amp micro1A

Later,

Bob

[FloridaRT]

Hate to tell you this, Summit gives free shipping here in the states.

Fan control was $24.88

Bob

[jaak]

Since this mod runs the fans in series, if one fan is unglugged you will have no fans with this mod, until the computer hicks on the high fan.

Actually, the design of the vehicle is such that low speed runs the two fans in series, and high speed runs them in parallel. All the mod does is control them the same way the FCM does, without the FCM knowing.

what exactly does this do , is this essentially the same as the gsm fan mod ? basically it makes your cooling fans run more ?

The GSM mod makes one fan run on high speed. So you suck cool air in on one side of the rad, and some of it gets pulled back on the other side to be recirculated. Not the best way to do it.

The one relay mod will kick in both fans at low speed, so you're not pulling heated air back through the rad. If you do all three relays, then you have full control of high and low speeds for both fans.

[95ttoplt1]

Actually, the design of the vehicle is such that low speed runs the two fans in series, and high speed runs them in parallel. All the mod does is control them the same way the FCM does, without the FCM knowing.


Exactley, I have one fan unplugged right now because it is bad. So I have no low speed fans, just one on high when it gets the that temp, way the heck to hot.

Hate to tell you this, Summit gives free shipping here in the states.

Fan control was $24.88

Bob

I know that makes it hurt even more :(


Well, all the parts are on their way to me, just have to visit Radio Shack today and buy the diode.

Radio Shack part#276-1101..........less than a $1 each, will buy 2, since I ordered 2 relays.

Diode # 1N4001 30amp micro1A

Later,

Bob


Cool, I love radio shack!! But there isn't one over here :(

You can also get the diodes off Ebay, 10 for a buck including shipping. I honestly don't know what kind of diode I used, but it works. I jacked it out of an old phone :)

I'm such a tight ass :mrgreen:

[jaak]

Exactley, I have one fan unplugged right now because it is bad. So I have no low speed fans, just one on high when it gets the that temp, way the heck to hot.

Ah.. Right, forgot about that. Well, if you're lucky, the bad fan is the same one controlled by high speed relay. If that's the case, move the low speed relay over to the high speed position and your circuit will control the one fan for high speed instead. Unless that's the bad one, then that won't work. But you could use three relays, as I've shown in the other thread, to push it in to high speed mode.

Nice sig! :)

[FloridaRT]

Just got back from Radio Shack, the Diodes come 2 in a package, cost me all of $.59...........with tax it was $.63. I can handle that, LOL.

Looked at their inline fuses, was not impressed, will pick one up at the auto store.

Just a spend thrift..................according to my wife, she is the tight wad.

Bob..................waiting for my relays.

[95ttoplt1]

What is the fuse going to be used for??

[FloridaRT]

I will install an inline fuse in the wire that goes to ground, I always like to put in a fuse when I do anything electrical on my car. Just a safety precaution, call me a worry wart....................

Cheap safety.............won't do any harm, will it?

Didn't you put in a fuse on your installation? I thought you did.

Bob

[95ttoplt1]

I will install an inline fuse in the wire that goes to ground, I always like to put in a fuse when I do anything electrical on my car. Just a safety precaution, call me a worry wart....................

Cheap safety.............won't do any harm, will it?

Didn't you put in a fuse on your installation? I thought you did.

Bob

Nope I didn't use a fuse.

Using one will in no way affect the mod. If it makes you feel better that is all that counts.

I did not use one as this is a ground wire.

I might now just to be safe :)

Good idea

[jaak]

Actually, a good idea! I haven't looked at the current draw on the relay to energise it, but it might not be a bad idea to put something perhaps around twice that current, on as a fuse. I certainly won't hurt.

[95ttoplt1]

The fan control is rated at 20 amps, But it shouldn't take near that much to energize the relay.

Maybe some one could measure the AMP's with a DVOM?? I can maybe tommorow at work.

[FloridaRT]

Okay Jaak (is that your name?),

I have some questions and some observations that I made looking under the hood.

1. First thing I noticed when I printed out your original post, was that your posting is too wide for printing, you lose the last 18 letters on the right side - no big deal, I just went back and filled in the missing letters. They are not really "missing", just cutoff by the printer.

2. Your car is a Charger SRT-8, mine is a Magnum RT, so a few things are different under the hood. There is hardly any room around the radiator to push in the probe, I have a large radiator shroud covering the radiator, did you have to move the shoud to insert the probe? There is no way that I have the room to insert the probe as in your photo - the shroud covers ALL of the radiator by the inlet hose.

3. The Diode is a lot smaller than shown in your photos, at least I think so. Your photos must be bigger than normal, your later photos showing the Diode installation - show your finger and the size of the Diode. Yes, I have the correct Diode, I was just surprised at how small they are. No big deal, I just wanted to point it out to others who might be doing this installation.

4. The wiring of the adjustable thermostat, I have a question. The wiring instructions that come with the kit, are for wiring up the fan with a 12 volt source. For example: connect "C" terminal to the positive lead on the fan, connect "2" terminal to positive lead for automatic operation.

The fan controller has 3 terminals, ("C", "2" and a "1"), explain what terminals we use and how you wired yours. We are only grounding out the fan relay, so what terminals on the fan controller do we use?

5. I am guessing that we just run a ground wire (horn mount) to the "2" terminal and a wire from the "C" terminal to the relay (diode). Am I right?

Thanks again,

Bob

[95ttoplt1]

Okay Jaak (is that your name?),

Nope I'm Troy, I used the relay instructions from Jaak

I have some questions and some observations that I made looking under the hood.

1. First thing I noticed when I printed out your original post, was that your posting is too wide for printing, you lose the last 18 letters on the right side - no big deal, I just went back and filled in the missing letters. They are not really "missing", just cutoff by the printer.

Sorry How do I cahange that?? I never thought about printing it as I just take my computer out with me :)

2. Your car is a Charger SRT-8, mine is a Magnum RT, so a few things are different under the hood. There is hardly any room around the radiator to push in the probe, I have a large radiator shroud covering the radiator, did you have to move the shoud to insert the probe? There is no way that I have the room to insert the probe as in your photo - the shroud covers ALL of the radiator by the inlet hose.

My probe passes over the top of the radiator to the engine side, and then is inserted into the radiator. I'm not sure what yours looks like, a picture might help me help you :). I have all sorts of coolers in fron of the radiator and this wuld make it pretty much impossible to insert from the front.

3. The Diode is a lot smaller than shown in your photos, at least I think so. Your photos must be bigger than normal, your later photos showing the Diode installation - show your finger and the size of the Diode. Yes, I have the correct Diode, I was just surprised at how small they are. No big deal, I just wanted to point it out to others who might be doing this installation.

Yes they are small and that is the most difficult part of the mod. The diodes are small, I'd say the body is about 1/8 inch long.

4. The wiring of the adjustable thermostat, I have a question. The wiring instructions that come with the kit, are for wiring up the fan with a 12 volt source. For example: connect "C" terminal to the positive lead on the fan, connect "2" terminal to positive lead for automatic operation.

My instructions(from summit) showed 3 poles but I only had 2 on my control. It does not matter how you connect them or what kind of circuit you are running(power or ground), Does you controller have 3 poles?? I just went and check mine again I definatley only have 2.

I threw my directions away, can you scan and post yours and I can give you terminal numbers

The controller is actually very simple. When it reaches the set temp. It connnects to the poles energizing the fan(power or ground however you have it wired)

The fan controller has 3 terminals, ("C", "2" and a "1"), explain what terminals we use and how you wired yours. We are only grounding out the fan relay, so what terminals on the fan controller do we use?

5. I am guessing that we just run a ground wire (horn mount) to the "2" terminal and a wire from the "C" terminal to the relay (diode). Am I right?

When wired correctly, the desired temp will connect 2 of the poles, supplying a ground to the diode in the relay

Thanks again,

Bob

If you have any more q's post them up. Thanks for helping and being the "guinea pig"

[FloridaRT]

Sorry Troy, I know you were not Jaak, must be old age setting in.

Here is a photo of the adj. temp control I got, it does have 3 terminals.
After reading the instructions again, I am sure that the "C" wire goes to the Diode, and the "2" wire goes to the ground (horn mount).

Hope the photo is okay, am not good at scaning....yes, I do have a scanner.

I also got my relays today, I have the cover off and managed to separate the lugs on that terminal.....all set to wire and solder.

About the radiator probe, did you place yours near the top of the radiator , or at the botom of the radiator? I know it is supposed to go by the inlet, but is the inlet at the top or bottom? Do we have a reversed flow radiator? From your photo showing the probe inserted, I can't tell if it is at the top or bottom of the radiator.

Not sure if you can make the posting "narrower" for printing, I just wondered if you were aware of it.

My photo is too big , will have to resize it.
Bob

[FloridaRT]

Photo try..........................Bob

the terminal on the left is "C"

the middle terminal is "2"

The terminal on the right is "1"

as seen in the photo.

Also just noticed on the body of the adjustable control body, that there is a skematic drawing, it shows that "C" is the common lug and it can switch between "1" or "2", depending I suppose on the temperature of the probe. I guess one side is normally open and the other is normally closed. Will have to hook up my Ohmn meter and check it out.
Plus put the probe is some hot water and test it again, hope the wife has a candy thermoeter.............

Pretty sure I have to use terminals C & 2

Bob

[jaak]

Looks a lot like an old hot tub thermostat!

http://www.hottubessentials.com/spa_parts_thermostats.asp

http://www.midamerica-parts.com/thermostat.html

Except these turn off when a temperature is reached, not turn on...

[FloridaRT]

LOL, I agree..............

I will be testing out the terminals today with my Volt/Ohmn meter, seeing which terminals have continuity. Will test again with pan of hot/boiling water. Also test out setting of adjustable temp control switch.

Still need to find a spot on the radiator to insert the probe. So where is the inlet hose on our cars? Is it the top or bottom hose? Do we have reverse flow radiators? Will have to feel the hoses to see which is the hotter one.

Later,

Bob

[FloridaRT]

Okay, finished testing out the Adj. Temp. Control module, to see what terminals to use. Here are the results:

150 degrees and cooler, terminals C & 2 are open, C & 1 are connected.

150 degrees and hotter, terminals C & 2 are connected, C & 1 are open.

So C & 2 are the terminals touse for the fan mod.

Depending on where you have the knob set to, you can dial in the temperature you want for the fans to kick on.

I played with the setting until I got a connection between terminals C & 2 at about 180 degrees. Just turn the knob back and forth until you get it right.

Interesting to note that you can use the control to turn things on or off at a set temperature, depending on which terminals you use.

Now what would we want to turn OFF at normal engine temperature??

Any ideas????

Later, time for Dr. Phil, LOL

Bob

[jaak]

Now what would we want to turn OFF at normal engine temperature??

The heater for the Hot Tub? LOL! OK, someone chop a Magnum and put a tub in the back!!!

[95ttoplt1]

Thanks BOB, I will take a video of where my Probe is located. Keep in mind while it may turn on at 150 degrees this is measured at the probe, not where the PCM is getting its reading. I have my turned all the way down and it turns on at 180 buy the EVIC reading.

[FloridaRT]

I know that I will have to fine tune the adj. setting, once I get everything installed. I have the EVIC and will use the temp. reading there to make the final adjustment.

After more looking at my radiator and underhood, I will insert the probe into the radiator fins from the front of the car. Will do so as close to the top hose as possible, may have to remove a horn to have access. Will install the horn after I do the probe insert, only problem doing it this way, is that I can't put the probe cover on after the install.

I might think about putting the probe into the top hose, just afraid of having a minor leak.

Next step is to solder up the Bosch relay, was easy to take apart - glad I have small hands. A small soldering iron will also help.

Later, time for lunch.

Bob

[95ttoplt1]

I don't have the cover on mine. Sorry I didn't get to video today it got dark while I was yelling at the dealer. I will try and get it tommorow if you can wait. If not it will be here for the next guy.

[FloridaRT]

Hey, No hurry - I work slooooooooow, LOL.

Hell to get old, slows you down big time.......................................

Bob

[jaak]

I'm going to try a different way of soldering in to the relay tonight, to see if it's any easier. Basically I'll put the diode in differently, solder it to the tab, solder the wire on, then cut the tab.

Sounds easy in principle, but may not be so in reality. But I'm hopeful it will make it a bit easier for those that want to do the relay mod, to deal with that tiny coil wire!

[95ttoplt1]

I'm going to try a different way of soldering in to the relay tonight, to see if it's any easier. Basically I'll put the diode in differently, solder it to the tab, solder the wire on, then cut the tab.

Sounds easy in principle, but may not be so in reality. But I'm hopeful it will make it a bit easier for those that want to do the relay mod, to deal with that tiny coil wire!

Thats the part that kicked my ass and prompted the Bosch relay route.

If you can do it as you describe that would make it much easier.

With the Bosch's they have 2 small tabs welded together and you just split them apart and solder the diode to each one.

[ferret]

I used the Bosch realy and found it is very simple to modify. I plugged it into the high speed fan socket which I use when I'm at the track. It is nice that all I have to do while in the staging area is flip on the switch. When I'm not racing it works as normal. I tried to use the OEM realy and after 3 of them gave up. It was good to see the post on the Bosch product. Not sure if I will use the thermostat mod or not but it looks pretty simple If I want to. Thanks for the tip(s).

[95ttoplt1]

I used the Bosch realy and found it is very simple to modify. I plugged it into the high speed fan socket which I use when I'm at the track. It is nice that all I have to do while in the staging area is flip on the switch. When I'm not racing it works as normal. I tried to use the OEM realy and after 3 of them gave up. It was good to see the post on the Bosch product. Not sure if I will use the thermostat mod or not but it looks pretty simple If I want to. Thanks for the tip(s).

Glad it worked for ya:thumbs_u:

[BillyDsl]

I'm postin best wishes to Bob in the other thread, ya'll got me dizzy following these two. The other being jaak's mystery wire post.. lol

Jaak do we have a source for the stock relays that you are modifying?. You must at the rate you are using them up. I wanted to leave my orig in tack and grab a few to experiment with like yourself.
Was thinking if we could find a good price on a lot of say 20? I might setup and do the mod and let the guys have emm for whatever the cost is. Just a thought.

BillyD.. :thumbs_u:

[mcinfantry]

pretty cool thread. im headed to NAPA!

heres my .02

click http://www.napaonline.com/

in the "Non-NAPA Part No." field type (or cut and paste) 0332209159

- or -

in the "NAPA Part No." field type (or cut and paste) MPE AR143SB

and its $8.49

or, write it down, drive over and buy it.

[mcinfantry]

if the fan comes on at 180, and the t-stat is 180, then the fan runs non-stop? correct?

[95ttoplt1]

No they kick on and off just like the stock fans with the stock configuration.

[FloridaRT]

More about my fan shroud today, I got the chance to look at another Magnum RT - namely the radiator and the shroud. This car also had room to plug in the temp. probe, my RT does not! Oh well, I will find a spot to plug that sucker in. I guess there is some play or room, to mount the shroud one way or another - some extra clearance.

Cooler weather is here in Florida now, so no big rush to get the fan mod working.

Bob

[95ttoplt1]

Can you take some pictures of the passanger side top engine side of the radiator?? I will take pics of mine and maybe we can see what is different

[FloridaRT]

Finally found a spot to insert the temperature probe in the radiator, spotted it while doing the Blink-Blink mod. Hope to finish up the fan mod install today, my relay is all set to go and I tested it this morning, turns both fans on when I ground the wire.

So cool!

Bob A.

[GoldNnasty]

This is a Great Mod! :friday:

I have a question:
Does the coil of the aftermarket relay need a resistor in parallel to keep from throwing a CEL? (if you use the original relay it has the resistor)

I have been reading waaaaay too much lately, and it appears that the factory manual shows a resistor???

Thimpkin waaaay tooooo much:mrgreen:

:popcorn:

[95ttoplt1]

This is a Great Mod! :friday:

I have a question:
Does the coil of the aftermarket relay need a resistor in parallel to keep from throwing a CEL? (if you use the original relay it has the resistor)

I have been reading waaaaay too much lately, and it appears that the factory manual shows a resistor???

Thimpkin waaaay tooooo much:mrgreen:

:popcorn:

You don't need the resistor if you use the Bosch part number listed above. It has the resistor built in and is working fine in my car.

[GoldNnasty]

You don't need the resistor if you use the Bosch part number listed above. It has the resistor built in and is working fine in my car.


Thanks!:mrgreen:

I will need one then, I got mine from a local electronics store with the same ratings (except resistor). So, now I need to CRAM 2lbs of stuff into 1lb box!

The resistor in question should be 680 ohms in parallel with the coil if not using Bosch relay (this info from jaak from another thread)

(Always trying to save money, but not work)
"Work smarter, not harder".............buy the Bosch!

Heads up for everyone

[FloridaRT]

Okay guys and gals, I am done!!!!!!!!!!!!!!!!!

Just finished up my fan mod right now and it works great!

Fans kick on when the engine temp gets to 180-182 degrees, cools the engine down to 179 real quick..............then shuts the fans off.

Took a picture of my install will try to post it here, may have to shrink it down. I mounted my temp controller a little different from Troy's, I mounted it in the engine compartment (out of the rain) on the fenderwell, near the fuse box. There is a metal tab there, not being used by anything. I also ran the ground wire to my mount bracket for the fan controller, short wires and easy to get to. I still want to install a inline fuse somewhere in the groind circuit - just for safety sake. Can just pull the fuse if I ever have to take the car in for service, so the mechanic does not get hurt by the fan.

Thanks again Troy for all your help!

Bob A.

[FloridaRT]

My Photo.

Bob

http://img.photobucket.com/albums/v431/MagnumRT/MVC-001F-1.jpg

[Meister]

Finally found a spot to insert the temperature probe in the radiator, spotted it while doing the Blink-Blink mod. Hope to finish up the fan mod install today, my relay is all set to go and I tested it this morning, turns both fans on when I ground the wire.

So cool!

Bob A.What's the Blink-Blink mod, Bob?

[mcinfantry]

ok, i just did the mod.

if you want, you can go back and add this to the first post.

the napa part number for the relay i gave is a CHINESE copy of the bosch. it is the hardest of the three to modify, imo.

i chose to use a preset 180 t-stat, and for my fan control i bought a Hayden fan t-stat part #3652 at pepboys, another part number that auto zone uses is 226206. this probe is self contained with the switch and is real easy to install.



this is a small probe that is preset at the factory to come on at 185, cut off at 170. its <$25 and the best part? it comes with a relay with the resistor installed. i opened it up and it is pretty nice. i modded the factory one and kept the other one as a spare for service calls. so the napa 191 ran 6 dollars. so i got the mod down to 31! no additional parts needed!

you dont need the harness in the picture...
http://midwayautosupply.com/images/PRODUCT/large/HAY-3652.jpg

[FloridaRT]

What's the Blink-Blink mod, Bob?

The Blink-Blink mod is one done by Funky Chicken, check out the Knowledge Base here for it. The 300's don't need it, as they already have the feature. For the Magnum's and Charger's, it makes the front side marker lights flash when you use your turn signals. In stock form, your front side marker lights do not flash at all. Looks cool at night and is a safety feature.

Check it out, a free mod.

Bob A.

[jaak]

Sorry for the delay on the alternate way of modding the stock relays, I've been kinda busy!

I have taken some pics and need to finish up tonight.

If the Bosch relays are easier, I say buy them and do the mod!

[iceman-5076Hemi]

Has anyone from Central Texas done this mod? Specifically from Austin / Killeen area? I know it may look easy, but when it comes to electrical, it scares the sh!t out of me. I can't solder for crap. I may even consider Houston / Dallas in the mix. I have family I can visit (as an excuse to travle specifically for the mod)...shhh, don't let the wifey know, She doesn't understand the obsession!!! :-) Any takers that wouldn't mind walking me through this in person?

Oh, not to take away from the post / instructions, but like I said electical and I don't get along. My luck is I would turn a vehicle that I paid 36K for, and that's only KBB'ing around 12K into scrap metal prices!!

[iceman-5076Hemi]

bump

[Familywagon]

Id love to take a better lookk at this one... Any chance of getting the pictures back?

[linuxrc]

interesting, but would like to have the photo's back.