Howdy all,

Starting in August, my AC clutch began disengaging after a few miles of driving (assumed it was due to the coil heating up). Finally it quit working altogether. I finally got around to digging into it this past week and determined the clutch was bad. I replaced the compressor/clutch assembly and it seems to be in working order now, but the clutch still won't engage through the clutch relay in the underhood fuse box. Here is where it gets weird for me. With the engine running and AC turned on:

1. I have 13V across the two relay coil terminals (seems to be getting a call for AC to the relay)
2. I have 13V across the two load terminals (voltage and ground to the clutch seem good)
3. If I jump the two load terminals the clutch engages (clutch seems to operate correctly)
4. If I swap the clutch and fan relays, the fan works with both, but the clutch works with neither (seems the relays are good)

My only thought is I'm somehow not getting good contact between the relay and the terminal but I have messed with that quite a bit to no avail. Anything else you guys can think of? I am a plumber rather than a mechanic, so it's very possible I am missing something.

Thanks,

 

See attached wiring diagram.

Your symptoms indicate the ground (enable) signal to the AC relay from ECM/PCM on pin 3 (red wire) is not being supplied. Either red wire is defective, defective ECM/PCM, or input to enable AC (pressure switch, relay module, gauge control module, or wiring) is faulty.

Suggest checking for voltage w/ a test light on pin 3 (red wire). If voltage is present, the ground signal is missing. If no voltage ground is being supplied.

good luck

 

Thanks for your help!

I do have 13V at pin 3, so it seems to be a grounding issue. I do not see a wiring diagram attached to your reply, but based on what I've researched it seems the pressure switch is part of the grounding run, is that correct? If so, how do I test a 4-pin pressure switch? All I can find online is 2 and 3 pin switches.

 

Sorry, I forgot the attachment.

Ground signal comes from PCM based on inputs, one of which is Pressure switch. See diagram.

Suggest accessing the AC control panel to see if DTC is set. See attachment.

good luck

 

So I went through the steps suggested and found a repair manual online. The clutch relay coil is not getting grounded through the PCM, correctly. Took it in and had it verified by a mechanic. They want ~$1700 to replace and program a new one. I have found many places online that claim to repair them for ~$200 with no programming necessary and a lifetime warranty. Does anyone have experience with these companies? One of them has an A+ with BBB but I can't seem to find any of the others on BBB or even find online review of them.

 

I sent out a PCM to some where in Atlanta. They did a good job for me on an 04 maxima I was fixing up for a friend. $200 sure does beat $1700. Whatever you do pay through PayPal at least you know you can get your money back if it does not work.

 

I know it's an old thread. But I'm having the same issue. I've tried searching with little luck. What route did you take to fix your issue?

 

Hello Everyone,
I am new here and I am trying to figure out what the problem is with the AC of my 2005 Accord V6 LX. I have checked everything that I can think of and can't seem to find out what is wrong.
Both the two fuses (one in the driver compartment and the other in the engine compartment) are both good.
The AC clutch relay is fine (found this out via did a relays swap)
The pressure switch is good (conducted a continuity test on lead 1 and 4 and those two leads are in the closed position while lead 2 & 3 are in the open position).
Freon pressure is good and line is full of freon.

For some reasons, the clutch relay is not receiving the signal when AC button on the dashboard is turned on. If I jump the two hot and load contacts (the two large contacts) of the clutch relay, then the ac clutch would turn on and cold air would be blowing. The only other possibilities that I can think of are a bad ground wire the is used to send the AC on/off signal to the relay or a bad climate control.

Has anyone had this same issue or have any ideas. Please help. Thank you very much.