A/c Issues

[AustinGT]

The a/c compressor in my '92 LS is not engaging- I can hit the "auto" button, and the a/c light will come on, but the compressor won't engage :cries: . The light is not blinking, and the interior fan is working fine- the previous owner replaced the compressor about 4-5 years ago with a reman Toyota compressor, and up until yesterday it was working fine- any ideas? I was really disappointed because I just got the car back from the shop where it has been for six weeks with an electrical problem that was finally solved- and if possible, I would love to avoid shelling out lots of money ...any ideas would be much appreciated. thanks!

[jbarhorst2]

Have someone else press the auto button while you watch the compressor and clutch.

Does anything happen?

If not, then you have an electrical issue. Perhaps a wire has been disconnected, a fuse has blown, or the clutch has gone bad.

Let us know what you find.

Tom

[wwest]

Have someone else press the auto button while you watch the compressor and clutch.

Does anything happen?

If not, then you have an electrical issue. Perhaps a wire has been disconnected, a fuse has blown, or the clutch has gone bad.

Let us know what you find.

Tom

The AC compressor clutch will not engage if the refrigerant charge is too low, the engine coolant temperature is approaching a point of being too high, at WOT, if the engine RPM is fairly high, or the OAT is below about 35F.

Your front/outside temperature sensor is disconnected or open. It's behind the front bumper in from of the A/C condensor.

Might also be a disconnected refrigerant pressure sensor/switch, that's mounted to the outside of the passenger side headlight.

[AustinGT]

Thanks for the ideas- I had the a/c recharged about two months ago, so the refrigerant should be good. Because the compressor is newer, I am hoping that the clutch is not bad. I will check those sensors- it is possible that those aren't fully connected as the mechanics had to really dig around to find that electical problem. I will let you know what happens.........If it is the clutch as jbarhorst2 suggested, is it possible to have the clutch replaced w/o replacing the whole compressor?

[AustinGT]

An update...I checked the pressure switch behind the headlight (which turned out to be little more work than expected- I think the lights have never been removed in 14 years!!!) and everything was connected all right, but about the outside temp sensor- what does it look like or where exactly is it? Also, when hitting either the "auto" button or the "a/c" button, the light goes on (but does not blink), the fan kicks in correctly, but the compressor does nothing. Were it any other time of the year, I would not be as concerned about it, but given that it is August in CA's San Joaquin valley, it has a rather high priority! Thanks for any input.....this forum is the best

[LScott400]

If you had the A/C recharged, then it has a leak. If only 2 months ago, you ought to be able to get a recheck under warranty. Having a set of gauges hooked up to it will show if the refrigerant level is too low to allow the compressor to engage.

[AustinGT]

Yep, it is sounding like I need an a/c shop to check it out- I am taking it in on Tues. to a local tire shop for new rear struts/shocks (which my LS has needed for a while) and I will probably take it to a a/c shop then...until then, I am crossing my fingers that it is not something major! Thanks guys for the advice so far, any additional inputs are always appreciated!

[jbarhorst2]

Good point WWEST. I completely passed over the low freon path.

AustinGT, yes, the clutch can be replaced without changing the compressor.

Tom

[AustinGT]

Thanks guys for all the help- it turned out that my 4-yr old compressor has a slow leak, but the shop said that they have had good luck with a compressor stop-leak they have used on other older LS's. I will try that and in the mean time start socking some money away!

This may sound dumb, but is it reasonable to expect another 50k or so from this car? I currently have 208k, but it has been very well maintained (new timing belt/60k service, new struts front and back, new steering rack, new fan belt tensioner, new alternator, new front brakes, - all within the last year)- and Mobil 1 and always 91 octane

Anyway, thanks again for all the great advice!

[VBdenny]

Mine does the exact same thing. The light comes on but the compressor doesn't engage. I added some R-12 and the compressor came on but it made a racket.

Anyone know what it costs to have the compressor replaced?

[AustinGT]

I have heard upwards of $900 with a Lexus compressor (and that is at an indie mechanic)- because of that, I decided to go the stop-leak route. I will take it back to the shop in two weeks where they said they will add some more freon if needed and more stop-leak. If anyone knows of a cheaper place to get a decent compressor, I'd be interested.......

[jbarhorst2]

Is it really the compressor that is leaking?

Or the system?

You may want to confirm with them.

If it is just the system in general, and not the compressor specifically, you could have them put some dye in the system to find the leak. Maybe it's an o-ring or something.

Might be worth an extra question.

Tom

[VBdenny]

yeah, for sure I would add a florescent dye and check it out with a blacklight before I replaced anything. I saw the compressor online from some place out of Florida for around $400 or something. I think you also need a new dryer and filter or something in case particles of metal got into the system.

I have a vacuum pump, gauges and 30lbs of R-12 on hand and I have no problem doing the R7R, what I need to know is what I need to do so I don't miss something and compromise the new compressor.