ac clutch won't engage
 

2004, 43k miles. AC blows hot. AC clutch won't engage. AC pressure checked, in the Red. Could this be coded to give me a starting point. Could this be electrical? Need guidance on a place to start looking.

Re: ac clutch won't engage
 

How 'bout the old, lame "check the fuses" response? :rolleyes:
Actually, "check the fuses" is plural, the documentation is not totally clear on what fuse is doing what, see my diagrams below.

Other than that, remember that the A/C Heater Control Module won't engage the clutch if:

• The Fan Speed Switch is "off" or at the first detent past off.
• The ECM has sensed that the engine is over temp. (Should be an indication on the temp needle and a warning light.)
• The FCM is not responding to the ECM's periodic communication pulses. (A warning light will be on, on the left end of teh days, looks like a little radiator and is called the "Low Coolant" light.)
• The system pressure is out of limits low or high.
• Probably other items I don't know about. (For example: I believe that the Evaporator temperature sensor indicating a very low evap temperature will cause the clutch to disengage, if the sensor is bad, the clutch may never engage - but I do not know this for sure.)

The control module is known to experience fractured solder connections between the two circuit boards, do not overlook the chance that this is the problem.


https://cimg6.ibsrv.net/gimg/www.cro...743bfa348f.jpghttps://cimg7.ibsrv.net/gimg/www.cro...d6d1d59e46.jpg

Re: ac clutch won't engage
 

Thank you. I'll let you know how everything works out. One of the best boards on the net.