I turned on the AC in my '96 today to be greeted only by warm air. The compressor clutch engages for a second or two, then disengages for maybe two or three seconds, etc., etc.

My knowledge of AC systems is minimal, so I'm wondering if this behavior indicate that the compressor is junk, or something else? The car has 105K and the compressor has never been replaced.

 

Sounds like you are very low on refrigerant. If the compressor is cycling rapidly most likely you are low on refrigerant.

You got a leak somewhere, if the vehicle had dye in it the leak should be easy to find with a black light and some yellow tinted glasses.

If not, have the system evacuated and then dye injected, then recharge with refrigerant. Yes, it will leak out but you will then be able to find the leak.

If you can find a shop with a electronic leak detection tool since you still probably have a little refrigerant left it may pick this up and you can fix the leak sooner and not have to recharge the system twice.

I would not recommend you run the a/c until you fix this. If you plan to keep the a/c I would get it fixed soon. Compressors sitting idle is bad for any length of time, over 1 month. Compressors are very expensive especially if they go bad and throw metal into the system.

 

I'm glad to hear you think it's only a low refrigerant problem. I'm going to try to get it to a shop this weekend, but I wanted to get some input from the forum before doing that.
Thanks.

 

I'd darn sure look for a friend or someone to help at home....a shop will turn a simple leak detection and recharge into an $1100 bill ! ! !

you can do it all for under $100 and have tool for next time. A recharge kit is $35, but you have to assume there is a slow leak somewhere if its low on charge.

 

What leesvet said, for sure. Too many AC guys equate their skill with that of a brain surgeon. Not saying they are without skills but seems to be overcharging to me.

 

Not to thread hijack, but what's used in the 96 vette A/C...R12 or R134?

 

My '94 uses R134 -- and all newer ones do, too. Low refrigerant level does not necessarily mean there is an identifiable leak. I had the same problem on my '99 Maxima and just refilled the system with a can from the auto parts store -- it's been good for several years now. I suppose old seals can allow slow leak down, but not enough to justify replacement. R134 is cheap.

 

I have to look at my records, but I was thinking my '96 had R12 in it when I bought it and I had it switched to R134. But I've had it almost 11 years, so I don't recall for sure.

 

As much as I like saving money, and knowing the job was done correctly, I have just never messed with A/C maintenance. I'm afraid that I'd either screw something up, or spend money on the supplies, and still not get it done.

I think I'm going to take it to a AAA shop, so hopefully they will be somewhat reputable.

 

93 was the last year for R12, 94 and up is R134a.

 

Guys, I am having the same issue with my 95. My pressure gauge was reading low, so I added 1 can and it was still doing that. I know those cheap gauges are for the birds and not super accurate. I was at 25psi before and then after it would kick on at 25psi and shut down at 45psi in a repeating cycle. I took out some freon to get the system at 40psi, but it is still cycling on and off. Not sure of what else to check?

TIA,
Chris

 

FWIW, I had two problems on my '96. A leak test showed that both the accumulator hose and the clutch cycling switch were leaking.

 

Pep Boys was $29.95 for a "performance test" which will get it leak tested. An Electronic Leak Detector is best since it's the only way to find an Evaporator leak. Whomever has 25/45 on their gages has a bad set of gages (or isn't giving enough info). All systems close the Low Pressure switch contacts at 45 to 50 psi and those contacts have to be closed to engage the compressor. High side should average 200 psi. '90 and up monitors how often the Low Pressure Switch opens and closes and if it's too rapid, uses that as indication of a low charge. With that, the system is shutdown and there should be a trouble code in the Panel. Nothing will work until that's cleared (disconnect and reconnect the battery). These later systems also monitor the pressure sensor on the high side and expect the signal to rise when the compressor engages. If it doesn't, that it'll shut it down though any Code will be in the PCM and not the Body Control Module. Most 15 to 20 year old systems need to be rebuilt and for quality parts, that's $800 and up depending on whether you do it yourself or take it to a shop. Most don't get these systems fixed (or fixed right) because the car isn't worth as much as it takes it to do it right.