Diagnosing AC compressor not working

[fliptuner]

I thought I was out of refrigerant so I got a DIY R12 kit and had at her.

Come to find my compressor isn't turning on. The pulley turns fine but doesn't engage when I turn the AC on. I can easily spin the outer part that's supposed to engage.

Is there any way I can bypass the relay to try turn it on manually? I just want to check if the relay is the problem or the compressor itself.

The AC fan turns on when hit the switch BTW, so I don't think the switch is the problem.

'92 EG Civic.

Anything else I should check for?

Thanks.

[Puck Luck]

compressor relay is in under hood fuse box. pull out the relay, and the 2 darker pins of the relay, are the ones you should be jumping in the fuse box to bypass the relay. Or you can leave the relay in and turn onthe ac and using a test light, see if there's power at the single wire to the compressor

[fliptuner]

Actually, I found the compressor relay right beside the driver's headlight.

I put 12V directly to the compressor and it turn on.

I'm not sure if I can short the pressure switch or if those even fail, or if I should just go ahead and start by replacing the relay.

[Puck Luck]

never really seen any problems with pressure switches, and yes you can jump the switch. But if the condensor fan turns on when the ac is turned on, then the pressure switch is ok. Cant remember if the condensor fan relay is beside the compressor relay, but try swapping those 2 relays around and see if the problem swaps around

[fliptuner]

Good point. Same relay then?

[Puck Luck]

i'm pretty sure they're the same

[fliptuner]

So I double checked everything before I started testing wires under the dash.

Turns out, when I put 12V directly to the compressor, it was 5mm from a wire clip (mounted on the compressor) that was covering sheathing, that was covering a broken wire. Luckily, I put the 12V at that point cause if I had done it any higher, the compressor wouldn't have turned on but everything before it would've fuctioned fine and I would've gone out hunting for a new compressor (after hours of testing) and had the same problem.

The funny thing is, it was a stupid place to put live voltage, being so low and right between the fan and the header. I actually broke apart a busted test light just to use the probe, to hook up to the + lead on a booster pack, just to reach down there to pierce the wire. Soldering the wire back together was a major PITA too.

I think what happened was when the motor swap was done, the compressor was left hanging or not supported well enough and the wire broke.

Anyways, system's all recharged and




Thanks for all the help!!!