A/c Problems

[howudodat]

A/C light blinks. Searches show this is a frozen compressor, however I just replaced the compressor about 3 months ago. Took the car to my mechanic and he checked the pressure on the system... 40lbs. Right where it should be. Also of note, sometimes the A/C works, othertimes it doesn't. Seems to be about 1 out of every 4 times I start the car the A/C will work. Any ideas?

91 LS400

Peter

[wwest]

A/C light blinks. Searches show this is a frozen compressor, however I just replaced the compressor about 3 months ago. Took the car to my mechanic and he checked the pressure on the system... 40lbs. Right where it should be. Also of note, sometimes the A/C works, othertimes it doesn't. Seems to be about 1 out of every 4 times I start the car the A/C will work. Any ideas?

91 LS400

Peter

Unplug/reseat, firmly, the relay that energizes the compressor clutch.

[SKperformance]

If that does not work it is your expansion valve .

[howudodat]

Have returned from a business trip and am ready to give a quick update.

Ran the A/C tests and after the A/C ran just fine for a couple of days. I thought all was solved. Sadly, it started mis-behaving again. So I will begin looking for the relay...just to make sure...where can I find this relay?

I've noticed also that *sometimes* I can have better luck firing up the compressor if I am going down the highway. So if it doesn't start up at first, I can jump on the highway, drive about 5 miles and then it will *usually* fire right up.

Peter

[RFeldes]

Check the rpm sensor connector attached to the bottom of the compressor.....

[howudodat]

ok..am going to put the car up on a lift tomorrow to check the sensor.

I found the relay/fuse box. There isn't a relay clearly marked A/C, only one I could find close was clmt. Is that it? Can the relay be swapped with another relay to check it, if so which one is recommended (I noticed not all the relays are the same).

Finally, I can no longer get the A/C to run no matter what speed I'm driving at.

Peter

PS. Thx for all the help so far.

[howudodat]

ok, took the car to my mechanics and we put it up on a lift. All connections seem tight. Found more info on the relay but still can't locate it. Where the heck is this thing?

Re-tested the freon level and checked to make sure the compressor wasn't frozen, all checks out.

Peter

[howudodat]

Finally found the relay, BTW for those who might come after me and search the forums, it's labled MG CLT in the fuse/relay box.

So....replaced the relay...still no go, A/C light blinks, no A/C. Any ideas before I dump a grand at the dealer?

Peter