Air conditioning Question

rlutz · #1 08-06-2017, 04:22 PM

AC on my '92 has given up. Just had a re-built compressor installed by the dealer on Friday. It worked for a little while.

But within the first day it would run for a while and then blow warm. Fan works on all 3 settings fine, but when I hit off and then hit auto, all was quiet (no fan, no compressor, no cold air).

If I stopped the car, turned off the ignition and re-started, it would start to blow cold again in "auto" but after a few minutes it would go warm.

This morning, it would only run cold for 15 sec or so, after an ignition off reset.

Now it won't blow cold at all. And it won't blow at all in auto mode, it will blow fine if I select low, med, high, but it's not cold.

I did the "auto, off" button together diagnostic. Came up 00, so I guess that's good.

Any ideas? It was converted to R-134a 5 years ago...

Blacky · #2 08-07-2017, 06:25 AM

Bring it back to the dealer and have them fix it properly. I'm sure they charged you a big bag of bucks$$$ for the replacement. The least they can do is make it work.
It sounds like all the freon leaked out.

rlutz · #3 08-07-2017, 06:50 AM

Actually they only charged $240 labor, I supplied the rebuilt compressor, as the new ones were very pricey $~800 vs $390 rebuilt.

This dealer turned-it around in one day as well. And they were blown away by the SVX. They'd never seen one, though one of the techs knew of one in the junkyard (which was also good to find out).

Hope it's just a bad o-ring...

Blacky · #4 08-07-2017, 09:10 AM

O-rings or the actual schrader valves where you fill and check pressures. I changed all the o-rings on one of mine and then discovered it was just the valve leaking. It could have been a 10 minute fix instead of hours.

rlutz · #5 08-07-2017, 11:29 AM

Dealer says there are no leaks. The intermittent operation is caused by compressor freezing. They recommend replacing the 3 temperature sensors. They say they'll do it if I can get the sensors. They say sensor replacement calls for removing the dash, but they'll try to minimize how much of that it really will take.

Anybody have a source for the temp sensors?

Is the replacement effort/access a killer (and better left to a dealer?)

rlutz · #6 08-08-2017, 07:00 PM

Anybody have a part number for the heater water temperature sensor that mounts into the heater core under the dash by the glove box?

I found the refrigerant and evaporator temp sensors, but can't find the one for the heater core...

I also found a "condenser temp sensor", part 73085PA020, that the dealer didn't mention. Is that one worth replacing too?

Blacky · #7 08-08-2017, 07:06 PM

I can't see all the sensors being bad. I've never heard of any of them being replaced actually.
If I were you I'd get a second opinion from an AC repair shop. Or just replace the ones that don't involve taking out the dash. That's going to get $$$.

It's hard to get any answers here on the forum now. All the activity seems to have moved over to facebook.

rlutz · #8 08-09-2017, 10:25 AM

I did a search on AC issues on the forum and there were a few recommendations to change the sensors. Though it wasn't clear if the third sensor was the heater core temp by the glove box, or the condenser temp sensor in the engine compartment.

Another reason that makes me think there's something electrical wrong here, is the ignition-off reset I mentioned in my first post, has been working for 3-4 years or so. When the AC wouldn't come on, or shut-off shortly after engine start, if I pulled over, shut off, and then started-up again, the AC would come on and run, often for the whole trip. It started getting worse and eventually quit this summer, so I took it in to the dealer and put in a new compressor.

The mechs say the system is getting too cold and is freezing up.