Expert: Roland Finston - 10/16/2011

Question
Hey Kevin,
My 2002 Chrysler Sebring 2.7L is overheating due to the fans not coming on. When I remove either relay when the car is running the fans kick on. That also sets a code. When I clear the code i'm back to square one. Roland delt with this problem on 9/26/11 with a some other guy named Enoch but then he went on vacation. You can probably look the conversation up. Anyways I don't have the luxury of wiring diagrams so I jumped the fans and they both work. Also when I supply my own ground to the relay when it's plugged in and the engine running it works great. That tells me that the relay block is not getting the ground signal from the PCM. Have you seen this problem before? The ECT sensor was just replaced but it's aftermarket. When I plug in my scanner I can read the ECT sig in degrees from the PCM so I know it's getting the signal. Is it common for the PCM's to go bad? Can you send me the wiring diagram for the PCM terminal to the relay block so I can check the wire before I condemn the PCM?
Thanks!

Answer
Hi Greg,
Each relay is activated by its own wire from the pcm. The low speed relay dark blue/tan wire is connected to pin 55 at the pcm, and the dark blue/pink wire from the high speed relay is connected to pin 69. At the relays' sockets those wires are attached to the outboard pins. The ect itself should read below 1,000 ohms at operating temp and the hotter the lower is the resistance. Its tan/black wire is connected to pin 26 at the pcm and it black/light blue sensor ground wire should be connected to pin 43. I would doubt the pcm is bad unless there is a code for that present. Check to be sure that the ect is actually reading the temp accurately as it might have an air bubble around it.
Roland
PS Sorry for the delay but I just found your question in the 'pool' to which it had been sent by Kevin. Please rate this answer and consider a nomination of me. Thanks