Got Fan Mod? Hot Weather is Coming!

[JimTurner]

ALL:

I have completed my Fan Mod design and was going to post in the morning after taking a quick peak at an SRT8, but since you are all SO interested, here you go:

http://members.cox.net/jdturneriii/300C/LXFanMod.pdf

** PLEASE NOTE THAT I HAVE NOT LOOKED AT THE SRT WIRING TO SEE IF THIS APPLIES OR NOT **

The Mod will offer you the following characteristics:

1. NO SPLICING INTO THE WIRING HARNESS! <-- A plus for me
2. NO CODES!
3. BOTH FANS ON HIGH WHEN ENGAGED!
4. OPTIONAL CONTROL WIRING to give you the following:
a. Turn Fans On ONLY When Engine is running
b. Turn Fans On Regardless of Engine State
c. Wire for BOTH options a. and b. (Slightly more complex wiring but not that bad).

I spent somewhere between $30 and $40 for the parts for this.

I've had this mod installed on my car for over 2 weeks and it works great.

Here is a picture of the installation.

http://members.cox.net/jdturneriii/300C/FanModInstalled.JPG

Please let me know if you have any questions.

Regards and Happy Cooling!

jimt

[Inked*Gamer]

Has anyone completed this mod. I have parts on order but was wonder wich wires go were, also would it be possible to do the 25 cent fan mod and just coneect a switch to it?

[jaak]

SRT's the same...

[PowerWagon896]

Has anyone completed this mod. I have parts on order but was wonder wich wires go were, also would it be possible to do the 25 cent fan mod and just coneect a switch to it?

No, the 25-cent fan mod replaces the relays with jumpers, this mod uses another set of relays to fire the OEM relays.

It is a bit intimidating, but I keep re-reading each part until I completely understand it. Then I move to the next step.

[jaak]

There is a simpler mod, but it requires cutting into the factory wires so this one's good if you want to be able to disconnect and remove it when you bring in the car for service.

[Rev.Hammer]

There is a simpler mod, but it requires cutting into the factory wires so this one's good if you want to be able to disconnect and remove it when you bring in the car for service.

Tell us about this o'mighty flinger of far out facts!!

[jaak]

LOL! You always crack me up Rev!

I worked it out when Jim did this one, but Jim's a heck of a lot better at documenting things...

I'll have to dig out my scribbles and document it. It's interesting, while doing this, I discovered the relays have a resistor built in to them in parallel with the coil. Got too many things to document and do! (LED flasher control, fan mod, rain sensor, IAT sensor fake out. Thankfully the Uconnect works... Where the heck is JetPilot with those harnesses, anyway?)

Jim's mod is great because you can yank out the whole thing and drive in to the dealer whistling like nothing's been touched, when you do your warranty claim.

I'll try to post the other one on the weekend, if I can. (Although Saturday is drag racing at Grand Bend. IHRA. So we'll see!)

[RobAGD]

I am doing the simple version of this mod, and its acting a bit weird. I have been talking with Jim about it, and when I get a little time I am going to start probing the relays and see why mine is not responding liek it should.

I have a 05 Magnum and i know the Jim did this on an 06 300c, so maybe some minor changes.

-R

[jaak]

Well, I couldn't resist, I went and dug up what I had planned, back when it was too friggen cold to want to do it. I had set it aside to do it in the warmer weather.

Well, the idea's great, it controls the stock relays and fakes out the FCM to think life is good and all is happiness. But, there's one hitch. I went out and actually looked at where I need to make the two cuts and connections, and it's inside the Integrated Power Module. There's two connections from the FCM to drive the relays, which is what I modify, but it's all inside the module, so access means drilling out the two plastic anchors and pulling the module apart, to get to the connections.

So in otherwords, while it's a more elegant solution electrically, it's not something I'd want to post on here for people to do as mechanically it's a bit of a PITA. You'd end up having to tear in to a module that would definately put you in a position of trashed warranty. (That's what happens when you work off schematics only!)

There is an alternate way of implementing this, that I'm going to look at. However, Jim's mod is certainly an excellent non-invasive way of doing this and I'd recommend it.

Jim, one note on your instructions. Instead of removing the anchor for the power lead, why not just remove the 13 mm nut that holds the wire on? You can swing the power lead out of the way, without removing the anchor and since you have to loosen it to tap off power for your relays, you'll have the wrench/socket in hand anyway.

I only mention this, because my anchor did not want to come out, and I really didn't want to snap it off, when I went to flip the IPM up to have a closer look.

[357mag]

jim is ther anyway to take a few more pics of the where the wires plug into?

[Nightshade]

:bump:

You were gonna post a better way to trigger the relays Jim.. it's warm out now.. heh


There is a simpler mod, but it requires cutting into the factory wires so this one's good if you want to be able to disconnect and remove it when you bring in the car for service.

[jaak]

Well, there's a couple of thoughts... The best wiring mod, means tearing apart the module, so while electrically it's good, mechanically it's a bit of a nightmare. So I bailed on that one.

Another way is to use a scan tool, as there is a command to turn on the fans to test them. The autoenginuity tool may be able to do this, but they're still working on updates for the LX and it's going to be two software revs away. Since it's a generic tool, it doesn't move as fast as I'd like for the LX. But it would be possible to send a command on CAN bus to turn on the fans, which would be the more elegant solution.

[Nightshade]

Well, there's a couple of thoughts... The best wiring mod, means tearing apart the module, so while electrically it's good, mechanically it's a bit of a nightmare. So I bailed on that one.

Another way is to use a scan tool, as there is a command to turn on the fans to test them. The autoenginuity tool may be able to do this, but they're still working on updates for the LX and it's going to be two software revs away. Since it's a generic tool, it doesn't move as fast as I'd like for the LX. But it would be possible to send a command on CAN bus to turn on the fans, which would be the more elegant solution.

Sounds like a job for MMMMMMMMMMMMMMMMMMMMMORPHEUS!

[jaak]

Anything that can talk on the bus would do it... Just have to know what the commands are!

[bigjim]

Hmmmm, I have no fan mod, stock thermostat (intended to keep the engine at the designed operating temp), I sat in traffic at the border returning from Toronto on the fourth of July weekend start (Canada day) for 3 hours with ac running and saw it stay at 208f (after I popped it into neutral, 238f in drive). I don't understand the desire to cool the engine into the excess emissions range (the temp helps "burn" the fuel more completely).

Can someone help me understand why you would want to always run out of spec for the few moments of added power (I understand the added 5 - 8% more horses it makes at lower temps from fooling it into more fuel)?

[PowerWagon896]

Hmmmm, I have no fan mod, stock thermostat (intended to keep the engine at the designed operating temp), I sat in traffic at the border returning from Toronto on the fourth of July weekend start (Canada day) for 3 hours with ac running and saw it stay at 208f (after I popped it into neutral, 238f in drive). I don't understand the desire to cool the engine into the excess emissions range (the temp helps "burn" the fuel more completely).

Can someone help me understand why you would want to always run out of spec for the few moments of added power (I understand the added 5 - 8% more horses it makes at lower temps from fooling it into more fuel)?


There's more to it than "fooling" it into more fuel".

More fuel does not = more HP. Peak HP AF ratio is very close to over lean. Working W/small air cooled engines magnifies this. Peak HP comes when the needle valve is leaned out. With a properly matched propeller limiting RPM @ static airspead, the mixture is leaned to maximum RPM (max HP) then richened slightly to insure the prevention of detonation.

Superchips adds HP by leaning out the AF ratio, not adding fuel. 91 octane is required to prevent detonation @ the leaner AF/advanced timing settings. More timing advance is part of the equasion, but the biggest HP boost associated W/cooler coolant temperatures comes from not (over) heating the incoming air as would occur in a "heat soaked" engine. A cooler incoming air charge is denser and therefore it makes more power. The "denser" air charge would also improve the AF ratio allowing more fuel to be burned without going too rich.

A cooler tstat/fan mod along with ice on the intake will make substatially more HP than a "heat soaked" engine. There will be no accelerated engine wear as long as the coolant temperature is @ or near 180*.

[bigjim]

So what you are talking about is raised combustion temps (increased oxides of nitrogen) and cooler water jacket temps to compensate for spewing acid out the tailpipe? Hmm interesting, still doesn't make sense to spew all the time for the wanted extra 5% of the time.

Of course my opinion.
Jim

[JimTurner]

:bump:

You were gonna post a better way to trigger the relays Jim.. it's warm out now.. heh

Dang,

Dunno how I missed this post. I found a temperature controller that is about $100 including a probe that is placed in the radiator coils. I would have wired that into the relay control circuit, and power. Seemed pretty simple, BUT...

... given that MagnumFreak thinks he can affect the fan control temp with Morpheus, I will wait for that and see. Gee, if Morpheus can do this, I will unplug my fan mod and reset to stock (one of the benefits of my plug-in mod).

Happy Cooling!

jimt:racing:

[quarky42]

Ya, loved your concept for the fan mod, Jim. Haven't done it yet but I have the parts. I may want to have a switchable fan even if I am able to program the fan temperatures since I live in the desert and have seen 220 and 225 on my temp display.

[Nightshade]

Oh, that was a response to Jaak (also named Jim)..

Even if they can lower the fan activation temp, would still be beneficial to have it running at the track.. any temp decrease will yield better times.. :)

:rock:

Dang,

Dunno how I missed this post. I found a temperature controller that is about $100 including a probe that is placed in the radiator coils. I would have wired that into the relay control circuit, and power. Seemed pretty simple, BUT...

... given that MagnumFreak thinks he can affect the fan control temp with Morpheus, I will wait for that and see. Gee, if Morpheus can do this, I will unplug my fan mod and reset to stock (one of the benefits of my plug-in mod).

Happy Cooling!

jimt:racing:

[JimTurner]

Oh, that was a response to Jaak (also named Jim)..



Great name! :beerchug:

jimt

[hemiwagn]

Great write-up Jim T!
You are hereby nominated as the mods documentation king!

[jaak]

Yeah, somewhere I did post an update to that... The problem is, while it would do it without additional relays, it means tearing in to the sealed unit which presents two issues:

1) It will be seen that the module has been "tampered with" and would be a source for a voided warranty, which none of us want to have.

2) It's not a trivial mod mechanically for most people, even if more straight forward electrically.

So as a result, while waiting for a CAN bus version of turn the fan on mod (which is really the most desirable), I'm going to build a version of Jim's mod! It's easily installable and you can pull it out with no evidence of being there. Can't beat that...

I was just reviewing Jim's document and one thing I noted Jim, is you mention Mode 1, 2 and 3. The factory configuration does not implement mode 2. It's either two fans on low, or two fans on high, not a single fan. You can see this in the wiring diagrams in the service manual as the two relays that control series/parallel operation for low/high speed, have their controlling circuit hard wired together.

Now where were those relays I bought.... Oh yeah, right there in that box! :mrgreen:

[JimTurner]

...I'm going to build a version of Jim's mod! It's easily installable and you can pull it out with no evidence of being there. Can't beat that...

I was just reviewing Jim's document and one thing I noted Jim, is you mention Mode 1, 2 and 3. The factory configuration does not implement mode 2. It's either two fans on low, or two fans on high, not a single fan. You can see this in the wiring diagrams in the service manual as the two relays that control series/parallel operation for low/high speed, have their controlling circuit hard wired together.

Now where were those relays I bought.... Oh yeah, right there in that box! :mrgreen:

So, I guess the Fan Controls either power relay #1 or all three. At one point, I was looking for a rotary switch would would turn 1, 1-2, and 1-2-3 on in succession. I thought I had found one, but did not have the time to investigate further. Too much life in the way at the moment.

Happy cooling!

jimt:racing:

[jaak]

Yeah, I know that feeling!

The Front Control Module (FCM) turns on one relay to power up the pair of the fans. The other two are wired together, so default is both in series for low speed, or energised, both to put them in parallel for high speed. The GSM mod puts one fan in high speed and totally disables the other fan, so if the FCM is calling for both in high speed, the GSM mod actually cripples it's ability to provide the cooling requested by the FCM, when enabled, from what I understand of it.

Your mod is currently the most comphrehensive solution, and my first choice for anyone who asks...

[Rt's RT]

so with the new installed switch off, it's working as bone stock, right?

[Token]

so with the new installed switch off, it's working as bone stock, right?That is correct. With the JT SImple mod you can have both fans come on at low speed, and they will go into high speed mode when the computer deems it necessary

[iceman-5076Hemi]

Anyone in the Austin / Killeen / Dallas / Houston area that could help me with this install? The directions are great, but me and electrical are not like pea's and carrots!! Any help would be much appreciated!! I will be installing the tstat tomorrow!! Happy motoring folks!!

[Rev.Hammer]

HOLEY BACK FROM THE DEAD!!!!!

http://citron.blueboard.cz/obrazky/zombie-psp.jpg

[BDA1855]

Sorry to dig this up again...

but im interested in this mod.

Will Jim's mod let the fans kick on high speed or only low speed?

[done]

Sorry to dig this up again...

but im interested in this mod.

Will Jim's mod let the fans kick on high speed or only low speed?

Both fans run at the same time on high speed.

[PowerWagon896]

Sorry to dig this up again...

but im interested in this mod.

Will Jim's mod let the fans kick on high speed or only low speed?


Jim's fan mod can easily be modified to allow 1, then both fans on high by using 2 switches.

1 controls the cutout relay & the top fan while the other switch, wired in series, controls the bottom fan but only when the cut out relay & top fan relay are energized.

IMO this is the best fan mod for racing as it allows easy control of the fans. I run both fans on high until I am staged & then shut off the fans @ the line to reduce alternator load & the resultant drag on engine output.

I also use the predator fan temperature settings for street driving W/a 185* TSTAT.

The Jim Turner Fan Mod works in conjunction W/the Predator settings as well as the stock settings.

[iceman-5076Hemi]

Bump for my request?

[JimTurner]

Hey there. Yes, I'm still around.:mrgreen:

The mod at this point is rather dated given the newer options available. However, if you want to be able to turn then on without Hal it works just fine. The other reason I set it up this way was the ability to remove it with virtually no evidence and no cutting of stock wiring.

Mine is still installed and I use it on occasion, but I don't go to the track.

If I was in Austin, I'd help you in a heartbeat, but I am in Sunny Southern California.:modding: :friday:

Part of the original instructions details how the stock fan system is controlled by the 3 relays. On "Low", the relays are thrown to put the 2 fans in series with each fan taking a 6 volt drop across the motor. On "High" the relays are thrown to allow the fans to run in parallel with each fan receiving 12 volts.

I controlled all relays with one switch running them on High (per the instructions), but as noted above, you can get creative on control switches. Just be careful if you do.

jimt

[PowerWagon896]

Hey there. Yes, I'm still around.:mrgreen:

The mod at this point is rather dated given the newer options available. However, if you want to be able to turn then on without Hal it works just fine. The other reason I set it up this way was the ability to remove it with virtually no evidence and no cutting of stock wiring.

Mine is still installed and I use it on occasion, but I don't go to the track.

If I was in Austin, I'd help you in a heartbeat, but I am in Sunny Southern California.:modding: :friday:

Part of the original instructions details how the stock fan system is controlled by the 3 relays. On "Low", the relays are thrown to put the 2 fans in series with each fan taking a 6 volt drop across the motor. On "High" the relays are thrown to allow the fans to run in parallel with each fan receiving 12 volts.

I controlled all relays with one switch running them on High (per the instructions), but as noted above, you can get creative on control switches. Just be careful if you do.

jimt

Yes Jim caution is in order. On your single switch mod, all three relay control wires are controled by 1 switch. The ground side of the circuit is the switched side.

In my dual control option, I ground the relays in the engine compartment & run low amperage power from the cabin tapping into the cigarette lighter circuit.

Then, all that is neccessary is to combine the cutout relay control wire W/1 of the fan control relay control wires. This will isolate the stock fan control system & run 1 of the fans on high.

The 2nd switch is then powered off the 1 st switch (wired in series) & is used to power the second fan relay control circuit. The second fan can not be powered up W/O the stock circuits interupted & the 1st fan running.

This can still be accomplished W/the switches controlling the ground circuit as in your original design but I wanted LED lighted rocker switches. That made it neccessary to reverse the circuit & switch the hot side of the relay control circuits.