My 2000 Silverado's air conditioner stops cooling intermitantly but comes back on after a while.
Anyone have a clue why?
Thanks for any help.

 

check the pressure in your ac lines

you may not have enough freon in your lines also make sure your clutch is kicking in sometimes they get stuck and make sure its not leaking or a valve can go bad inside (it will hiss sometimes)

also check your blend door motor (that will cause the exact problem your talking about)

 

ya these are all probable causes some simple test that i would check is: 1 there is a wiring connector that hooks to a sensor that is threaded into your accumulator take the connector off an take a paper clip an jump both wires that will kick the clutch on. and do this while the engine is running. you should see the compressor running if the clutch is working correctly. this test will turn it on even when there is no refrigerant in the system. so i would only do this for test purposes not a permeant or temporary fix.
2.check the system for leaks put some (not alot) dye in the system and recharge it and let it go for a couple of weeks and then take a black light and look over all of the ac components for signs of leaks
other than that your compressor may be going bad to this problem sounds like a compressor issue to me

 

Thanks for the replies.
It cools just fine when it is working, but when it stops cooling, I hit the on/off switch a few times and it comes back on and cools fine again.
Does that narrow it down any?
Thanks, Mike

 

Had a similar problem on my 2000 4.8L Silverado a few years back. As it turned out it was a simple wire that controlled the compressor clutch. It had a intermittent short to ground. I modified a shrink sleeve to mend the wire, and it has worked fine ever since. It's been about 5 or 6 years now.

Unfortunately, with vehicles having so many electronics nowadays, there is no such thing as a simple diagnosis. Both Wiked's and 88 Silverado's posts might hold the answer for you.

 

Have you ever had work done to your A/C system? Could be moisture in the system, or your clutch might be the issue, as others have described.

A simple test is to see if your A/C stops working when you accelerate. I'm not sure if your truck operates the blend door by vacuum, but if the actuator is getting low vacuum, it'll default to heat instead of cool. Under light acceleration, see if it stops cooling.

 

I've had the truck for 6 years and never had a problem until now. It stops cooling at different times. Usually, while I'm just cruising down the highway. I hit the on/off switch once or twice and it starts cooling again. I don't think it is leaking because it is just as cold now as it was before I started having the problem. If it is the clutch, can you replace it without vacuum and recharge?

 

As far as I know, you do not need to recover your refrigerant to replace the clutch, but it will be much easier to do so while the compressor is on the bench, as there are usually snap rings in there holding the coil on. From what I see on autozone's website, the kit that you'll need comes with the clutch and the coil assembly.

To know if it is indeed your clutch, start the truck, and turn on the A/C to MAX (recirculation, panel vents, highest blower speed and coldest temp) and grab a flashlight and look at the clutch and see if the clutch plate and hub both are moving at the same speed. If they look out of sync, then your clutch is either worn out, or the air gap is incorrect. You need a feeler gauge to check the gap. This is a nice looking guide to go by. Note that he gives specifics about a compressor that is most likely not installed on your truck. Just follow his instructions on actually checking the gap. SpringerPop's Compressor Clutch Air Gap