My fan hasn't been turning on unless I'm running the AC, programming a tune, or if I unplug the drivers side sensor. The fans obviously working. I've replaced the drivers side sensor and still the same. Is it the pass side sensor that controls it? Without any OBDII testing equipment, I don't really know where to go from here. Could it be the computer? It's just strange that it still turns on when I program a tune....
Might be the low speed relay inside the CCRM. Use the wiring diagram in the back of your Haynes/Chilton manual to find the low speed output of the CCRM
Ive been researching all night, and im finding alot of CCRM problems being the issue. Gonna check out the diagram and test the outputs of the module once the car warms up. May wire up hi/low speed switch in the mean time
The fans turn on when you're tuning because that's what happens when the PCM is accessed in such a way. Running diagnostics will do that as well, along with turning on the AC. At least that's the deal on my F body's, but it probably applies to our Mustangs as well...
