1992 Chevy S-10 A/C Problem

Can anyone help me, I have a 1992 Chevy S-10 Blazer that I cannot get the compressor clutch to kick in. Should you be able to apply voltage to the compressor connector and the clutch engage or is it just a switch? Anyway, not sure where else to go, I am a student and don't have alot of money to get it fixed. Guy I bought it from said it had been working great, system is charged but I did not think that would make a differece whether clutch would engage or not. Any help would be appreciated.

you will need a multimeter to do this. check the a/c fuse. if its good check for voltage to the compressor clutch. there should be a connector at the compressor where you can check for this. if there is voltage then your compressor clutch is bad. if there isnt voltage then you need to check the a/c relay. jump terminals 30 and 87 of the relay socket with a fused jumper wire. if terminal 30 has voltage then you should see the compressor clutch engage varifying that your a/c relay is bad. if the compressor clutch doesnt engage then you have a wiring problem from the fuse to terminal 30 of the a/c relay since you have no power at terminal 30 of the relay. if you have no idea what i just wrote then you need to bring it to a shop.

Yes the clutch should engage if you apply voltage+ and ground- to it directly. You will notice a slight "arc" at the connection when this is done, this is normal. Do not arc the wires at the battery, batteries are explosive. If you notice a heavy arc and clutch does not engage then the clutch has a short-circuit and the circuit fuse will probably be blown. If you notice no arc and clutch does not engage it has a open-circuit and clutch is again faulty. If the clutch does engage then I would move upstream to the low pressure switch. I'm not sure on your S-10 but it may be plumbed into the drier (a aluminum canister mounted close to the firewall, the larger hose from your compressor will go to it) This switch will stop current flow to the compressor clutch if your system is low on refrigerant or this switch could be faulty. You can also do your clutch test here by-passing this switch but do not run system with this switch by-passed as complete failure of the a/c system could result.

Go the the ACCUMULATOR Low pressure switch on the accumulator(large can shaped silver or black )
Remove the wire connector and use a wire and jump across the connector. Compressor should turn on.
Fireplug

Went to the accumulator, jumped accross the wires and clutch engaged. Does this mean the system is low on R-12?

Thanks

Jim

The system is low or the switch is bad .When you jump the connector and the a/c clutch runs does the air get very cold if it does its a bad switch if air is only a little cold you are low on freon

The system is low or the switch is bad .When you jump the connector and the a/c clutch runs does the air get very cold if it does its a bad switch if air is only a little cold you are low on freon

I agree with Fireplug: you probably have a low state of charge in the A/C system. It's a pressure safety switch in the system to prevent damage to the compressor becuase the R12 level is low (therefore the lubricating oil present in the system is low also). You'll have to bring it in for a "fill up". Unfortunately R12 is no longer made (holes in the ozone and all that) and of course the stuff is now priced like gold...maybe even more....But, you might not need that much R12 and the cost to refill the system might not be too unreasonable... The other alternative is the 2/55 system; 2 windows open and 55mph.

mike

The switch on the accumulator is not the safety switch, it is the low pressure switch. This causes the compressor to cycle. If it is not turning on the clutch the pressure is too low (no charge) or the switch is bad. The high pressure switch is either on the compressor or on the discharge line from the compressor but before the condensor.

If its low just switch it to r-134 system. Its very easy. Hell I have done 5 for people who did not want to spend a dime. Drain system install new R-134 valve fitting on low side and refill with R-134.
It all comes in a retro kit at most parts stores.
Hell I have done 2 Caravans 2 S-10 Trucks ,1 Beretta all are now 3 years old and still working.
Fireplug

92 should already be 134, should say on your compressor.

'92 is NOT R134, it is R12. 1995, I believe was the changeover year.

Yeah you're right, I think in 92 only a select few, by 94 most and in 95 all had to be 134, my mistake!

Thank you, yes, when you jump accross the switch it does run but does not get cold, It had worked OK las summer. Can you tell me how much a recharge might be?

If you're going to charge with R-12 It's going to be expensive just because of the price of the refrigerant. Your 12 year old truck might have just lost enough charge over the years and not actually have a "leak" but because of the cost of R-12 it would be a gamble to charge without checking for leaks and leaks can sometimes be hard to find, you might not find a leak but later find that your a/c system has stopped working again. If you plan on keeping the truck for a while I would follow Fireplug's advice and have the system converted to 134.

The cost for at kit is about 30 bucks and takes about 10 min to do. And you can buy R-134 in cans in the auto parts store also .Get a can of R-134 oil with dye in it and use a black light to find any leaks.
ON the old R-12 systems look at all the a/c hoses for any wet spots that look like oil leaks. Look at the entire system for any oil spots or a bunch of dirt in any one area . R-12 oil will pull in dirt and hold it in a leaking area.
Fireplug.
To switch over to R-134 YOU DO NOT HAVE TO CHANGE ANY PART OF THE A/C SYSTEM.

Please don't take this the wrong way Fireplug.

I had a '92 1500 pickup earlier this summer. The guy thought he would convert it to R134. Went to one of the parts stores (Advance Auto?) and bought a kit.

He vented what was remaining of the R12. He installed the adaptors, he then used a vacuum pump to evacuate the system and then charged the system with what came in the kit. It lasted for a short time, how much time, he wasn't clear. However, the compressor went out.

The customer brought in the cans, why he still had them who knows. It turned out that he added PAG oil instead of ester. The system had to be flushed and redone.

Not trying to be a chicken little here, just a word of caution, Do not use PAG oil on a retrofit. Make sure that the oil is compatible with the mineral based oil in the R12 system.

The cost for at kit is about 30 bucks and takes about 10 min to do. And you can buy R-134 in cans in the auto parts store also .Get a can of R-134 oil with dye in it and use a black light to find any leaks.
ON the old R-12 systems look at all the a/c hoses for any wet spots that look like oil leaks. Look at the entire system for any oil spots or a bunch of dirt in any one area . R-12 oil will pull in dirt and hold it in a leaking area.
Fireplug.
To switch over to R-134 YOU DO NOT HAVE TO CHANGE ANY PART OF THE A/C SYSTEM.

When you retro to 134a only use 80% of the amount of r12 it called for. If your retro kit dos not have Ester oil in it get it. It won't hurt the old O rings. Also 134a builds more presure at the orafice (the sprayer in the line just before the evaporator) this can cause a loss of power during cycling. Change the orafice to a ford blue one. All GM's use the same orafice. Ford has three. You want the blue one. You won't feel the cycle as much.