Last october, I hit a deer. The ensuing repair work was a headache to say the least, with multiple trips to the GMC dealer for follow-up repairs after the initial 5-6 week repair time. I thought everything was alright until this morning when the engine overheated. I almost never get stopped in traffic, and rarely let the car sit idle, so it wasn't until today, in a "fast" food drive-thru line that the "high engine temp" warning came on. Driving the car brought the temp down to normal, but after another two minutes idle, the temp started to rise again. I checked under the hood to find that the cooling fan is not turning on. I'm assuming this is due to bad repair work after the deer hit, but I'd like to avoid a trip back to the dealer. So, does anyone have any suggestions as to what may be preventing the fan from coming on? Fuse? Relay? Bad connection? Bad fan? Bad sensor?

Any help or suggestions will be appreciated.

Thanks,
Adam

 

weird, if the fan is not turning on, it could be multiple probs, it could be a bad fan, blown fuse, it could be a bad ECT sensor, the thermostat could be stuck closed. id guess ECT sensor. but that usally should throw a CEL

 

I have the same problem. I checked the voltage and it is getting to the control module. I pushed straight pins into the black and white wire near the fan motor and I am getting 12 volts from both sides. Is that a motor winding short or is the control module sending power to both power (black) and neutral (white)? If it is the conrol module, can I open it up and fix it? If it is the motor winding, can I trace it and fix it?

Thanks for any help!
Pat

 

Disconnect the plug to the fan check the resistance/continuity of the neutral wire to ground. It will read as an open circuit.
It has to be a bad wire or connection to ground. You wouldn't be able to have 12 volts on the common wire if it was connected to ground (assuming you had one probe of your meter on the the common wire and the other probe on your engine).