97 Cutlass Supreme A/C Problems

[97Cutlass]

I have an 97 Cutlass and I'm having A/C problems. Last summer the A/C pump started leaking and eventually stopped working. This weekend I just replaced the pump, dryer, and orifice valve. I oiled the new pump properly and the charged the system. The clutch never engaged once. The system is full but the pump doesn't turn on. I checked the under hood fuse and relay. The fuse was good. I swithed the fuel pump relay and the a/c relay to find them both good. Next I checked the electrical connection on the pump. I tested the voltage and got 0.10 volts with the a/c on or off. What voltage should I read at the connector? I am at my wits end with this problem and have no other ideas what it could be. I do think it could be electrical but don't know where to begin.

[IsaacHayes]

Did you suck it down to a complete vacuum for 30mins min before charging?

You have to do that when you break the seal on the system.

It sounds like it's not sending the signal to turn on the compressor, so that sounds like the pressure is out of spec in the system so it won't kick on the compressor. Like when it leaks down it won't turn on. It could be over pressurized if you didn't get the air out first...

[97Cutlass]

Did you suck it down to a complete vacuum for 30mins min before charging?

You have to do that when you break the seal on the system.

It sounds like it's not sending the signal to turn on the compressor, so that sounds like the pressure is out of spec in the system so it won't kick on the compressor. Like when it leaks down it won't turn on. It could be over pressurized if you didn't get the air out first...

How do I do this? Do I have to start over?

[sharkey]

if that is the case it should throw a code. what i would do is get a wiring schematic and work my way back from the a/c clutch. make sure your ground is good (continueity check from the plug to the - terminal of the battery) if that checks out, start tracing the 12v+ back.

if you have access to a scan tool with a data stream, verify that the pcm is turning the a/c on.

[IsaacHayes]

eh... yeah you really don't want air in the system. Or the moisture (reason for keeping the vacuum pump going for 30mins minimum). Sorry to say it but yeah you're gonna have to do it right... Do a search for procedures. And it helps to have a full set of gauges to read everything and do it right. Do you have those or just the quick charge thing at the department stores?

[97Cutlass]

I hooked my Snap-On scanner to the car last night and this is what it read.

A/C Hi Side (V) 1.00 A/C Hi Side (PSI) 77
A/C Request Yes A/C Clutch CMD Off
A/C Press. To High No WOT A/C Disabled No

I ran a fuctional test on the A/C relay with the car off and you could hear it switching on and off. Then I started the car, turned on the A/C and it still didn't work. Next I used the scanner to switch the relay on and the A/C came on. I could shut the A/C off on the dash and it would stay on as long as the scanner was hooked up. As soon as the scanner was off the A/C would shut off. It appears I have enough refridgerent in the system. What I don't understand is the above A/C Clutch CMD Off. What am I missing?

[IsaacHayes]

Hmmmmm. Dunno about that. I just know its bad to charge it with air and moisture in the system since it's not made to run with that crap in there. Probably need a new dryer on there too now.

I can't think of anything right now.... I can't remember what the psi should be off right now. What does hi side V mean?

How many cans did you add?

[97Cutlass]

Hmmmmm. Dunno about that. I just know its bad to charge it with air and moisture in the system since it's not made to run with that crap in there. Probably need a new dryer on there too now.

I can't think of anything right now.... I can't remember what the psi should be off right now. What does hi side V mean?

How many cans did you add?

I think the hi side V is volts. I'm not sure. I put in one oil and 1 1/2 cans of refrigerent. I've done this many times and have never had this problem.

[IsaacHayes]

1.5 cans? My system takes 3 cans when I break the system (and then suck it to a vacuum). Since you only have 1.5 cans in there I'd suck it down to a vacuum and let it sit for at least 30mins. Hopefully the air and moisture in the air that is in the system hasn't saturated the dryer. Then add the right amount of cans the system says. 1.5 cans sounds awfully low.

What temperature was this at when you scanned it? The static pressure may be too low. http://www.aircondition.com/tech/questions/82/ has some information.

You've done this many times? But did you ever take a component OFF of the system and expose the system to air?

[97Cutlass]

1.5 cans? My system takes 3 cans when I break the system (and then suck it to a vacuum). Since you only have 1.5 cans in there I'd suck it down to a vacuum and let it sit for at least 30mins. Hopefully the air and moisture in the air that is in the system hasn't saturated the dryer. Then add the right amount of cans the system says. 1.5 cans sounds awfully low.

What temperature was this at when you scanned it? The static pressure may be too low. http://www.aircondition.com/tech/questions/82/ has some information.

You've done this many times? But did you ever take a component OFF of the system and expose the system to air?

I couldn't get anymore in the system. What do you use to suck it down to a vacuum. The car was cold when I scanned it. I've taken the compressor off this car before and it charged up just fine.

[IsaacHayes]

You couldn't get anymore because you had air in the system.

You need an electric vacuum pump. I have used this one before. It hooks right up to the manifold gauges. I have seen other people use a compressor from a refrigerator they salvaged and made into a vacuum pump. Leave on for min 30mins to boil off any moisture.

When adding the 134a, do no invert the can so the compressor sucks in liquid as that can damage it as it tries to compress liquid. Instead to get the 134a out of the can faster, get a container of HOT tap water and put it in that. That will help keep the can from frosting up and then the car can suck the 134a down quicker. I did that to get all 3 cans in my car after I had it on the vacuum. (you don't break the vacuum when adding the 134a).

[GPXSS]

if you have an air compressor that can keep up with the demands, these work: http://www.harborfreight.com/cpi/cta...emnumber=92475

I used one when I did my R-12 charge a few years ago. Gauges told me it did get down to full vacuum and held, so for $9.99 it does the job.

It sounds to me like your pressure switch is not allowing the compressor to kick in, either because of too low of a pressure or too high of a pressure (prob too low)

[IsaacHayes]

You don't want air in the system because it doesn't compress into a liquid to do the job like the freon, and also moisture will freeze up in the system and clog it up.