Help with AC problems

[tallfreak]

I have been having problems with my a/c lately. Sometimes it will come on, some times it won't. Well this weekend I drove about an hour on the interstate trying to get it to come on and it never did. I pulled over and thumped the relay and it started working. I didn't even make it to the interstate again before it quit. I found a parts store and got a new relay and it worked for the next 120 miles or so. When I pulled over, I thumped the relay and it worked for about 5 minutes.

I bought a new relay that worked all the way back home with no problems. Does anyone have any suggestions? I thought maybe the diode was bad and the clutch was drawing too much current on start-up and frying the relays, but I don't know very much about it.

I am looking into a Killer Chiller, but I don't want to spend the money on one if it won't work when I want it to.

 

[tallfreak]

Anyone?

 

[blownsvtlightning]

make sure no lose connections to the relay and check the clutch gap, make sure it is not too wide.. a business card should fit snug between it and the pulley.

 

[tallfreak]

How do I check for loose connections? As far as I can tell they are all making good contact. None of the connectors are pushed down or damaged and they are all leaving marks on the relay terminals.

 

[tallfreak]

Does anyone have a wiring schematic for the a/c system? I can't find one anywhere.

 

[Hollywoood]

I had a similar problem a year ago... It turned out to be the pressure switch on the accumulator. I replaced it, and no more troubles!

 

[tallfreak]

That is what I have been wondering. I will try and replace it soon. Do I have to evacuate the system to replace it?

 

[tallfreak]

Ok I figured it out. A few of the relay contacts were bad. But I evacuated and recharged it anyways and the high side pressure was getting up to 450PSI before I hit the high speed fan button. Shouldn't the high pressure switch have cut the compressor off before it got that high? The a/c machine I was using pegs at 500PSI.