1jimbo

Hey guys and ladies my 2000 Silverado's a/c works fine when I first start up the truck but once it cycles a few times the compressor won't kick back on. And when I jump it at the relay it still won't come on. But when the truck cools off it will cycles again .is there a sensor or something around the clutch

A/C cycles while the compressor is cool. But when it warms up it stops cycling . Any suggestions?
I can feel the engine rpm raise up as if the compressor is coming on but then nothing. I hear a click around the compressor?

oilcanhenry

You really need to put am A/C gauge set on to see what your pressures are. Might have a bad pressure control switch, or likely in need of R-134A.

1jimbo

the low side is between 35 and 45 and the hi side is 170 to 200 psi

oilcanhenry

Those numbers are well within normal range.Likely a bad relay or a bad low pressure cut off switch.

Is your A/C compressor continuing to turn over all the time? What kind of noise do you hear?

The compressor has no switch (unless its an old R-4 Harrison, which I dont believe it is since those
were discontinued after R-134A was introduced.) They supposedly needed R-12 mineral oil to keep
the seal tight, yet I converted many to PAG oil/ R-134A with no issues at all..

ACDELCO 1522144A ACDelco 15-50156. Could be an orifice issue as well, of course but unlikely.

1jimbo

Thanks I put my meter on the connection at the compressor I have 13.70 volts as it cycles off 0 volts . But when it compressor warms up it gets the 13.70 volts but the compressor doesn't kick on after awhile I can start up the truck and it works fine again. I'm beginning to think the compressor is going bad.

oilcanhenry

Its possible, but more likely a high or low cutout switch malfunctioning.. but unlikely.compressor,, if system runs normally for awhile. Of course at 19 years its going to have some wear and tear..

1jimbo

Thanks for info I noticed today that the compressor works fine but when I rasied the idol the compressor kicked off and would not come back on is there some kind of sensor im missing?

1jimbo

noticed today while I was running my a/c that when I first start the a/c it will run fine.But when I revied the engine up the compressor
kicked off and would not come back on. I now wonder if the cut-out sensor is bad? HELP

oilcanhenry

When you go off idle A/C pressures will increase. Perhaps that is setting off the high pressure switch.It might have gone twitchy on you.

1jimbo

my 2000 Silverado 2500 has a problem the pressure low side 45 and the hi side 200 .but when I get on the road the compressor kicks off and will not come back on. Even if I jump the relay the compressor it won't come back on.Something is not right can anyone tell me what the red cut -out sensor on the back of compressor? also is there some one who has a wiring diagram for the a/c.
Also I changed out the low pressure and hi pressure switchs HELP