ac wiring diagram

Hi anyone, My ac does not work, in cycles on and off. There was a noise around the ac pulley. there was a what it looks like a sensor attached on the ac compressor with 3 pin, I do not know what it is for, Can somebody tell me and give me ac wiring diagram and how it works? I appreciate your help. Thank yoy

 

It is a compressor speed sensor, if there's a problem in that sensor or circuit or the cmpressor locks up the A/C amplifier will disable the compressor and you will get a flashing A/C light.
I can pull a system diagram when I get back to my computer but if your not getting a flashing light when it cycles out that sensor is most likely working.

 

Thanks for the reply Dm93, and send me the wiring diagram when you get a chance please, Yes I do get a flashing light when compressor cycles out. I did try to turn the the compressor with my hand, engine off, it does not look like the compressor is seized. Is there any other test that I can do? or I have a bad comp speed sensor?

 

Based on what you describe the clutch is slipping or there's a problem in the speed sensor or circuit, ideally you would need a scope to check the sensor but there is a method to check it with a multimeter and battery described on page 5 of the compressor inspection.
This should be all the info you need to diagnose, it's from the 06 FSM it should be the same but if your wiring doesn't match I can pull 07 diagrams from Mitchel.

 

Dm93 I dont have a scope but I do have a meter. Could you please tell me instruction on how to test the comp speed sensor or the clutch, and if you could tell me the sequence of operation of ac compressor? Thank you.

 

Thank you very much Dm93. I just saw your post. This will help me a lot.

 

No problem, if you need any other info I'll do what I can.

 

Apologies for posting in an old thread, but those docs are immensely helpful. Do we have a resistance chart for the evap sensor? Easy cheap part to diag before I move on. Thanks