A/C problem

hi, could my a/c have been over charged?it blows cold for 3 to 5 minutes then quits.at this time the compressor quits.sometimes it dosent turn on at all.its a 2000 4.0 xj.thanks for any help.

i would watch the clutch and see if its slipping. i had the same problem. would work then stop

Who charged it? Was it blowing warm before?

the dealer i got it from charged it.its not a big dealer.so i would imagine that they just put a can in from the auto parts store.when i got it it didnt work so i took it back to them.i talked to a mechanic that i use to work for and he said it is possible that it got over charged.if so it would act that way.the clutch works and then shuts off and doesnt come back on.didnt know if it could be the air gap that i have heard so much about on here or not.thank again for any help.

Well, unless you bought it "as is", I'd take it back to them. I could certainly be the air gap issue, could be overcharged, could be other things.

So after you shut it off, it takes a awhile for it to work again? If so, how long? Do you have to shut down and let the engine cool off before it works again?

well good question on how long before it works again.if it sits over nite it will work in the morning.the other day i went fishing and it was 95 degrees out.i was driving around the lakes im a member at and decided to turn it on to get 5 minutes of cool air but it never even cooled off.today i turned it on sitting in the drive when i first started it and it stayed on till i started to hold the engine at a higher rpm.

Need a gauge to see what is happening, but it sounds like when you rev the engine the compressor turns faster causing it to pump harder. This will cause the compressor to pump the low pressure side too far and shut off with the low pressure switch. You may need a recharge, but you need to check with a gauge to be sure or you may add too much(BAD).

So here's something you *can* try at home.

After you've driven around for a while and the AC has stopped working, leave the engine running, open the hood and verify the clutch is not engaged (center of the hub is not rotating. Don't touch anything!! Then shut the engine off.

Locate the wire coming from the clutch and follow it until you find the disconnect, and disconnect it.

Take a jumper lead and connect the clutch end of the wire to the + post on your battery. The clutch should engage. If not, press on the clutch plate and see if that gets it to engage. (Make sure engine off!). If it holds, then disconnect from battery, clutch should disengage and reconnect to battery. Clutch should re-engage. If not, press again. If it does engage when you press, it's likely the "air gap" issue.

After years of use, the clutch plates wear a bit and the coil weakens. Once hot, the coil doesn't have enough strength to close the gap. Removing one of the shims (washers) tightens the gap enough to work again.

You should also check the resistance of the coil to make sure it's within specs.

You can download the compressor manual at the Sanden website (www.sanden.com) for the specs on the coil and gap.

thanks,i will try that

couldnt get it to engage.so now what should i do?this mean the clutch is bad?thanks again

If you couldn't get it to engage with a direct jump, your clutch is likely toast. You can confirm with a simple resistance reading.

k,thanks again