04 Lincoln LS V8 cooling fan

[Dfonner]

My 04 V8 LS cooling fan barely turns and the car overheats because of it. I have tested that the fan is fully functional by bypassing any control and I am able to get the fan to come on full blast by doing so. I have also checked to ensure that the ecu is sending a signal to fan to activate it and it appears to do so. My question is this- where is the fan control module located? Would a faulty control module cause my fan to act this way?

If I run the heater, the temp stays in the operating range and does not overheat and no error codes are being thrown.

Any thoughts, guidance, suggestions?

Thank you,

Fonner

 

[joegr]

The electronic fan control is built into the fan motor and can't be replaced separately. If it goes to high speed by disconnecting the control wire from the PCM, then it is probably okay (but not for 100% certain).
The PCM controls the fan speed by means of a PWM signal on the control line. You have to look at the signal with an oscilloscope to verify it. The PCM sets the fan speed based on inputs form the temperature sensors, climate control, and ABS module (car speed, no need for the fan if you are going 70 MPH down the road).
The post linked below shows some scope captures from a good PCM going to a good fan.

http://www.lincolnvscadillac.com/showthread.php?t=69519

 

[Dfonner]

Thanks Joegr