[alialfa]

The cooling fan (under 6 months old) has suddenly quit days after a coolant service I had done. However, I don't believe the two are related. System is bled of all air and filled to the right amount of premixed orange OAT-type coolant meeting Chrysler MS-12106.

Here's what I've done so far:

• Started the car cold and let it get to temperature, though it never leveled off and continued climbing at a steady rate.
• At 95C or 203F I heard a distinct click from the TIPM which I presume was the fan relay.
• All hoses feel warm/hot, thermostat is fine
• A/C on full blast with "Max A/C" and front defroster enabled, still the fan won't kick on.
• The Rad Fan Fuse (F22) was inspected and tested for continuity, it was fine. I probed the socket and couldn't get a voltage but I believe this is user error. Forgot to probe F37, I'll do so tonight but I'm sure what to look for.
• I disconnected the large connector to the fan (in picture below) and probed across the +/-. It showed 12V but it did so even after I shut the engine off. I don't know what to think of that seeing as I couldn't get a voltage at F22.

Note: all testing with the multimeter was done above normal operating temperature and with A/C as described above, so the cooling fan should have been on.

After probing the fan connector, I triggered a MIL with code P0480. I don't believe this has any significance seeing as the circuit was indeed open and it wasn't there before I disconnected it.

Any instructions on how to replace the fan would greatly appreciated, though I'll hold off until I diagnose it first.

Thanks

 

[alialfa]

Thanks for the information about the connector, I'll fiddle with it a little more tonight. Any idea on F37 (50 amp red that control the PWM fan module)? It's a the 6 cyl engine for the cooling fan removal.

 

[alialfa]

PCM/TCM flash with a transmission quick learn was done a couple of months ago, it made a noticeable improvement in shift quality considering shift 4-5 is no longer an issue and the transmission is smoother overall. I'm convinced nothing can fix 2-3's harshness but I digress.

I see from service library info that fan removal is not too bad assuming I can jack the car high enough, but I'm working with a hydraulic jack and regular jack stands.

I'll give it a try but if its too dodgy I'll have to forfeit this job to a shop, I choose life. If there are any tips and tricks on how to get the front of the car higher with what I've got, I'm all ears.

Cheers

 

[alialfa]

Things got interesting, so the fan works but only with A/C on, even then it shuts off half way on my drive to work then I have to pull over shut off the engine and turn it back on to get the fan.

I had kind of hoped the fan was bad since a warranty replacement had just shipped, but this turned into a real head scratcher.

Still haven't gotten a voltage from the F22/F37 cause the probes on my meter are too large.

Anyone know what's going on???

 

[alialfa]

Thanks for you input folks, here's what I've done in response.
With respect to wire chaffing, I've inspected the harness and although the black tape is missing, the wires are intact. Also, ground G903A was scrubbed with wire brush and sprayed with contact cleaner after evidence of greenish white crusties.

What lilshawn said was very pertinent to my case. I should have mentioned that the coolant service I had done to begin with was because my upper radiator hose blew off and sprayed the front of the engine bay with coolant. You can see in an image below how the old fan module is covered in orange spots which is dried coolant.
Now I did get a warrantied cooling fan replacement, so I decided to experiment with the PWM control module that is part of the assembly and easily removable. Ample contact cleaner was used and allowed to evaporate on either side of the PWM connection points as well as the fan harness connectors. Here are the results of my testing:

New Module with New Fan: Fan INOP in all cases
New Module with Old Fan: Fan INOP in all cases
Old Module with New Fan: Fan on with A/C on
Old Module with Old Fan: Fan on with A/C on

Testing with the new fan was done by resting it on the engine bay and there was just enough slack to run the wires down. In every case, I allowed the coolant to reach 225F (way above normal operating temp), before turning on A/C to see if it makes a difference. This was done with the vehicle in park with the hood up.

Here's what I make of this. In both cases with the new PWM Module, the fan was completely dead. I suspect the module is possibly faulty. Not sure if it means anything, but the continuity values between fan side pins and harness side pins were identical to the old PWM fan module.
With the old module, both cases presented the same, fan works with A/C on, but no response to the cooling system circuit. How many coolant temperature sensors are there? The sensor that sends it's info to the dash works great. Does the cooling system recieve it's temperature reading from the same sensor as the dash or is there a secondary one? By the way, 4 months ago I had to replaced the oil cooler and put in a new OEM coolant temperature sensor.

 

[alialfa]

Photos for reference.