LX Forums Forum banner

Rad fan wiring bad?

396 Views 11 Replies 4 Participants Last post by  Tpabayflyer
Recently got a 2010 SRT8 Challenger with a tick and fixed it up with new cam/lifters porting, long tubes, tune etc….. 6.1 runs great but fans will not turn on? AC on or off no bueno…. Fan relays have 12V available but 25c Hotwire mod is a nogo….. running direct power and ground to the fan connectors with the wiring plug removed fans work fine? Left and right both work when powered up….. anybody seen this before? Looks like the issue is either on the fuse box or large wire bundle going to the fans? Thanks in advance…….
1 - 12 of 12 Posts
Do you have AlfaOBD, you can test fire them with it. How hot do you let it get before shutting it down.
You say the fans work if you feed 12 volts directly to them. I would work my way back the the front control module and see where the don't work anymore. When you find a place where they do not work, the problem is between there and the fans.
Good luck.
Ok thanks…. Is the front control module one of the square relays in the fuse box? Or is there another fan control box somewhere? I’m not familiar with the alfaOBD system but I do have the HP Tuners for reading/deleting trouble codes……. Car gets hot when not moving but as long as I have airflow while moving, temps of course are good…. Temps got up to 240 and rising so I had to shut it down…. I hot wired the right side fan last time I was out and it kept the temps under co trail running all the time…. Car is sitting now while I try and find a solution…..
Product Schematic Font Rectangle Parallel

The front power distribution center is in the engine compartment. This center contains fuses and relays. It is combined with the Front Control Module (FCM) to form the Totally Integrated Power Module (TIPM).

Cavity Cartridge Fuse Mini-Fuse Description 1 — 15 Amp Blue Washer Motor
2 — 25 Amp Neutral Power-train Control Module (PCM)
3 — 25 Amp Neutral Ignition Run / Start
4 — 25 Amp Neutral Alternator / EGR Solenoid
5 — 15 Amp Blue Engine Control Module (Diesel)
6 — 25 Amp Neutral Ignition Coils / Injectors / Short Runner Valve
7 — 25 Amp Neutral Interior Lamps / Under Hood Lamps (Police)
8 — 25 Amp Neutral Starter
9 — — Starter Relay
10 30 Amp Pink — Windshield Wiper
11 30 Amp Pink — Anti-Lock Brake System (ABS) Valves
12 40 Amp Green — Radiator Fan
13 50 Amp Red — Anti-Lock Brake System (ABS) Pump Motor
14 — — —
15 50 Amp Red — Radiator Fan
16 — — Wiper On / Off Relay
17 — — Wiper High / Low Relay
18 — — Radiator Fan Control Relay
19 — — Radiator Fan High / Low Control Relay
20 — — Radiator Fan High Relay
21 — — Auto Shut Down Relay
26 — — Run / Start Relay
See less See more
  • Like
Reactions: 1
Thanks for that great diagram…Picture saved!!…. Best one I have seen yet👍 Yeah, wiring is not my wheelhouse and when these things happen, it’s a nightmare….. I would rather replace the cam again then deal with this……. When stuff fails with no trouble codes, there could be so many things that could have caused this…. Poor ground…. Corrosion, short,…. Etc….. Modern electronics are great until they’re not…….
With AlfaOBD you can test fire just about everything on the Car. See fans testers here.

Font Parallel Number Screenshot Rectangle
See less See more
  • Like
Reactions: 1
Well, I bought the AlfaOBD but having issues connecting with my laptop using a elm327 interface….. Alfa looks like a damn nice scanner👍
I guess your Apple phone is why you didn't go with the app?
Well, I bought the AlfaOBD but having issues connecting with my laptop using a elm327 interface….. Alfa looks like a damn nice scanner👍
Which elm327 are you using? I've found some of the really cheap ones ($10 or so) aren't great on compatibility. A good one I've found is the BAFX Products OBD2 reader. I've used the bluetooth one (about $23) with my phone and Torque Pro, has worked on my 2006 300C SRT8, 2006 Silverado SS, and several 2018-2022 Ford F450 work trucks. I see they now have a Wifi version available for $28, might be the ticket for use with your laptop.

I'd check with the AlfaOBD people first though and see why you're having connectivity issues and maybe ask them specifically about the BAFX adapter before buying.

Which reminds me, tried finding mine the other day and it's disappeared, which sucks, because I rarely lose stuff. I had pulled it out of the toolbox to loan to a friend but he went ahead and put his truck in the shop first so I didn't get it to him.. now it's gone. :(

I got the OBD link BT and it works now with my windows laptop. I can get all the fault codes but. Not any real time data yet…..
But I did test fire the fans today and they both worked…. Fault codes set for fan1 and fan2 control circuit low?
U0101 code set for lost communication with TCM…. I’m having trans limp mode issues……eff….
1 - 12 of 12 Posts