One month ago I had the compressor and accumulator replaced. Cost over a grand! Now one month later the truck, a Chevy S10 4.3L, blows hot air. Most of the time when the engine is cold, the compressor clicks on and the accumulator feels cold. If I let it run for four or five minutes though the compressor shuts off on does not come back on. I took it back to the shop, they checked the relay but said when the compressor shuts off, their computer shows NO next to relay. I checked some of the grounds and the wires from the compressor going under the air intake for damage but found none. Any advice would be greatly appreciated. Thanks and I hope your cars are doing better than mine.

Jason

Compressors can cut off for several reasons. What did you mean by computer says "NO" at the relay?

Also - did they reuse the original clutch or a new one with new compressor?

T
Tom Greenleaf - MetroWest Boston - USA
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http://www.autoacsystems.com/tomgreenleaf/

When the truck was back in their shop for the fourth time, I stood back there and they showed me that the computer, hooked up to my computer was saying that it was not recieving anything from the AC relay. During this time the compressor was not turning. Also the clutch was replaced. I was wondering if the sensors at the compressor and accumalator maybe needed to be replaced. I checked the R134 level again and is perfect. I also reinsulated and checked the green and black wires from the compressor going under the air intake.

I have checked several grounds and they seem good. Is there a ground I am missing somewhere, maybe under the drivers side be the emergency brake. Sometime my windshield wipers work, sometimes they don't? Seems like there is an electrical short, loose connection, or loose ground somewhere to me. What do you think?

So far this is not rocket science. How the heck did you determine the the 134a charge was ok with the compressor not engaged? The only way to know that is to recover all refrigerant and weigh it! Pressures are approximations that are highly temperature dependant and mean almost nothing if system doesn't engage.

Ex: A pressure with system off either high or low side will read about the pressure in psi as the ambient temp in degrees F. Anything less you are near out of refrigerant! It's leaking!

If you want to see compressor come on just jumper wire the low side switch on your accumulator (I think it's there) if a two wire switch compressor will probably click on. You test for 12V there going in and at about 30psi pressure it makes it's own connection and disconnects when too low which guards against hydraulic lock at the compressor.

If no power to the switch you check out fuses and relays.

What year is this S-10 Blazer? If 93 or newer it has a high side switch to cut out compressor if too high but that's in the 300s psi. Don't mess with that switch. If you don't which is which don't mess with them at all.

Come visit the folks at www.autoACsystems.com/tomgreenleaf -- click on the CoolZone for A/C help,

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/