: Reasons for a/c compressor inop ?

07-20-04, 09:38 PM
Ok, first post here :hide:

my 96 deville came down with some issues in no time at all. Of course right when I was hitting 99k and getting ready to sell it.

First off. My a/c compressor clutch is not kicking on. Clutch spins fine and it never made any noises. Worked fine just before winter last year, never worked again once it got hot. I know they have a pressure sensor that will keep them from engaging when low on freon, but I checked it and its full , and would not take anymore since the compressor would not engage.

I checked all fuses dealing with the A/C system, and found nothing.

What could be some causes? Could the car having some serious codes and possibly being in "limp home mode" keep the A/C system inop?

Because. the other issues are poor drivablity. Shows horrible MPG average. Went from 22, down to 5-9 in what seemed like one day. Hesitates and just feels lacking overall.

Pulled codes and got ;
pco; 0135 O2 sensor , 1520 tranny range , 1599 engine near stall , 1626 theft deterant ( worn key) , 1660 cooling fan (? never seemed to have an issue) and IP 1552 which I cant find no matter where I search.

No other codes.

Resets codes as I found in my searches on this site and only
0680? (The keep alive mem one) and the IP1552 one stayed (of course since thats the one I cant find)

Sorry to have a post that goes all over for my first, but i wanted to lay it all out!

Lew 10 Fords for me , and one Caddy for the wife :shhh:

07-20-04, 11:47 PM
What pressure are you showing when you hooked up your gauges?

07-21-04, 12:29 AM
GT, I'm not a driveability tech, nor do I play one on TV, but that O2 failure will cause a lot of the drivability problems you're seeing. Of all the inputs on most all of GM's injection systems, the three most important are the MAP or MAF sensor, the coolant temp sensor, and the O2 sensor. Without that O2 sensor, you are going to run over rich, with the attendant problems. The cooling fan code could be tied to the coolant temp sensor. Your best bet is get the car to a driveability tech- a real one- and have them anylize the codes. They can check the A/C while they're at it.

(psst.... by the way- don't tell any one else, but I drive Citroens and Peugeots as regular transportation..... :suspect: )

07-21-04, 03:36 AM
Well, having someone else work on my cars is just completely out of the question.
I have come to the conclusion that I have to even do my own front end alignments. That and rebuilding an automatic tranny were the last things on the list, and the recent alignment fiasco I just went through on my Mustang (show car that took 1st in a recent national show) was the last straw. Blatantly tried ripping me off on ball joints that had less then 800 miles on them. Tire Kingdom which is owned by NTB were the bad guys there. I already do everything else from rebuilds, to paint and body work, to custom electrical harnesses.

I have plenty of tech freinds, but non that work on GM regularly, and I would be embarased to tell them I couldnt figure it out, :Poke:

Its just that I am not familure with the "standards" of this car. Mostly because I have not had to be. But now, all this popped up at once.

So is there anyway to tell if the car is in "limp home mode" that the A/C compressor would be inop?

Looks like that O2 will be a bear to get out, but not as bad as I feared. Looks like a long extention on an impact will get it right out. (one between fire wall and the engine)

Any word on code 1552?

The tranny range one appears to be dealing with the TPS sensor input verses vehical speed, which my guess relates to the O2 sensor making it run pig rich and sloppy.

07-21-04, 05:10 PM
You said the car runs bad and gas mileage fell...You need to go to basics.
You may be getting a false O2 code. Before you change it try to get the engine running better. Look around the web, there is a lot of info on false o2 codes. Bad plugs/wires, clogged/stuck injectors, fuel filter ever changed?, fuel pressure, air filter...The computer should sense misfire (esp as bad as you describe) but sometimes they don't.
The TPS may be the problem, check it with a VOM.

I asked you before, did you put gauges on the compressor?

07-21-04, 05:15 PM
The only thing that will put the car in "limp home mode" is excessive engine temp in the vicinity of 269 degrees.

07-22-04, 02:28 AM
first disconnect the _ battery cable for 3 min.reconnect start car and see if it gives message that freon is low and compressor will be shut off. if so you have a leak.

07-22-04, 07:04 PM
Thanks guys.

I reset the battery the other day, and NOW it does display that the coolant is low.

My guess is that it was high on the gauge because the compressor was not kicking on.
In my searching, I saw something about hooking up the hose, and then starting the car. Think that will work?

It seems to be running a little better , but not much. Think i am still going to replace the O2 sensors. Regular price is 72 bucks, and I am getting them for 50 , so I cant complain. I am a believe in replacing them every 30-50,000 miles, and I dont think this car ever had them done.

If that does not sure it, i am going to look into the airmeter and TPS inputs and see where they are at.

Thanks guys.

07-22-04, 09:19 PM
Yes, you need to have the codes cleard, the refrigerant can and hose hooked up (can upside down) and valve opened ready to go or as soon as you turn on the A/C to recharge it will detect low regfrigerant and turn off the compressor (catch 22).

07-23-04, 01:15 AM
Also, just to be clear..............

the low pressure side is the fitting on the passenger side and not the fitting up by the drivers side of the firewall, correct?

07-23-04, 10:42 AM
Yes, it's the fitting (technically it's a Schraeder valve) on the passenger side of the engine compartment near the strut tower. I believe that a home recharge kit won't even fit on the high pressure fitting, anyway.