ac clutch won't engage
Join Date: Jun 2009
Location: Fort Worth, Texas
Age: 64
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Re: ac clutch won't engage
How 'bout the old, lame "check the fuses" response?
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:
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.)
Last edited by pizzaguy; 07-22-2017 at 09:45 PM.