AC clutch not engaging when bypassing relay
My AC stopped working last summer but I never got around to fixing it. I now am troubleshooting it and noticed that if I try to bypass the AC relay by supplying 12 volts to the AC clutch from the fuse box, middle P/Y terminal of relay, the clutch does not engage. That would mean a broken wire somewhere as the current can't get to the clutch? Does anyone know where that wiring harness is routed? I will try 12 volts straight at the AC compressor to see if it engages the clutch.
Car is a 2005 Mazda 3 GT hatchback.
Re: AC clutch not engaging when bypassing relay
Either broken wire or the compressor (clutch electronics) are no good.
Access the compressor and check continuity with the volt meter of the cars side wiring to the relay. If that's good then you know ots the compressor
Re: AC clutch not engaging when bypassing relay
The AC compressor will not kick on if your refrigerant is too low; there is a pressure transducer in line with the electrical circuit. Check your refrigerant level too
Re: AC clutch not engaging when bypassing relay
Quote:
Originally Posted by
morganc
The AC compressor will not kick on if your refrigerant is too low; there is a pressure transducer in line with the electrical circuit. Check your refrigerant level too
Forgot about that, good point.
OP does state he is trying to bypass the relay and it's not clicking. If he is bypassing it, it should click regardless
Re: AC clutch not engaging when bypassing relay
Depends where the transducer is in the system; if it's after the relay then bypassing the relay still won't make a difference. OP, try jumping a 12v dummy wire right to the compressor terminal then work backwards from there.
Re: AC clutch not engaging when bypassing relay
I looked up the diagram on all data. Can't post at the moment. On my phone
Relay
Pin 30 power from battery
Pin 87 power going straight to the compressor magnetic clutch. Clutch is already grounded on other end
Pin 86 power from switched ignition source
Pin 85 ground from ecu. This will turn on the relay
The switch you are referring to feeds to the ECU
http://i11.photobucket.com/albums/a1...psjbscsawt.jpg
http://i11.photobucket.com/albums/a1...psi3ora3g5.jpg