2008 CX-9 No power to AC compressor

[fiddleman]

If you want to test the relay you can try swapping it with another identical relay. Usually there a few relay side by side in the fuse box that you can find one to swap with.

Did that still nothing

 

[puma]

i think you should follow the steps youri pointed out

 

[fiddleman]

OK, I’ve done my testing on the relay and here’s the what I have found pin number 30 on the AC relay is supposed to be the B+ so it stays hot all the time 87 is the load side. It should only be hot whenever the relay engages, therefore sending power on through to the AC compressor, well here’s the problem I have no power whatsoever no 12 V on pin number 30 regardless it never has no power, but I have power on the load side pin 87 all the time so to me it’s just backwards and whatever is causing this. I have no idea I don’t know where to look at anymore, but I feel like if I could get it figured out to where 30 has to be and 87 doesn’t have nothing until the AC is turned on my problem solved so on 30 and the fuses are good, I sure would appreciate it. Thank you.

 

[youri]

All i can say is to follow the diagnostic steps i proposed in the workshop manual.

Reading it I think the signal to the relay goes from the front climate control unit to the refrigerant pressure switch then to the PCM and then to the relay. Any fault in these systems could prevent the magnetic clutch from engaging.

The diagnostic procedure has various voltage check, etc to confirm each of those systems are still functional and narrow it down by elimination.

 

[fiddleman]

Thanks, I just don’t understand why there’s no B+ on pin 30 of the relay and that’s what everything I’ve read says it’s supposed to be hot all the time right off the battery and pin 87 is the pin going to the compressor but it’s just the opposite pin 87 is hot and 30 is not

 

[youri]

If you are correct that would be very odd.

First step would be to take a second look and confirm your are testing the correct relay. (AC relay).

The second step would be to check the cable leading from the relay/fuse box to the compressor magnetic clutch. I don’t see how 87 could possibly be hot, because i think it only goes to the compressor and nowhere else. That is why i am thinking maybe it is a diagnostic error. Otherwise if you are correct it would could be a short somewhere, but if 87 is indeed going directly to the compressor and it is hot, then i would think your compressor would be running all the time.

Note that i am just a DIY and only going from the wiring diagram. Trying to help but take my advice with a grain of salt. I could be totally wrong.

Also maybe if you put a few photos of the test you are doing it could help users here understand your situation

 

[fiddleman]

Okay folks update got it working it was the climate control head in the dash replaced that it’s working great now. Thanks to everyone for all your help with this I sure do appreciate u guys.