I've been reading most of the threads regaurding but none seem to fit what's going on.. my a/c shut off yesterday and i checked the pressure on low side and it was at 100psi way in the red, and compressor clutch never would kick on.. so it was sucked out and attempted to refill but the compressor still won't kick on.. I've checked fuses, relays, connections.. reset battery.. when switched to a/c the idle jumps like it's all reading, but it's not kicking the compressor on at all.. any ideas or things to try ??

greatly appreciatied in advane

 

I had same thing happen. The compressor has 3 parts the comp clutch assembly, the coil, and then the compressor itself. When it get hot there is a wire in the coil or something that separates and stops working. The thing is when it cools down the AC works again but after 10 to 15 minutes it stops. Once the AC guys replaced this parts it was all good. Its either this or your AC pressure switch? Good luck...

 

A/C compressor cycling switch sounds like the part your looking for.

 

mine does that. I'm going to end up changing the entire compressor.

I've changed:
condensor and drier.
refilled the system 4 times.
a/c computer
cleaned the evap core.

You could try and bypass the temp switch and run a jumper wire (it's on the compressor), and if it runs fine, then it's your compressor overheating.

 

there is a one pin connector on the top of the compressor, with your a/c turned on, backprobe that pin for voltage.

If it has 12 volts, but the compressor is not spinning then you will need a new a/c clutch (the electromagnet in the clutch assembly went bad)
If it does not have 12 volts then the computer is not commanding the compressor on, most likely due to a sensor input.

 

the thing that gets me, is why was it at 100psi on the low side to begin with.. shouldn't be over 50 at all..

 

ok so far I have

tested presure switch on high press line.. tests ok

pulled the single wire off that runs to compressor from radiator support, NO JUICE

ran 5 amp fused jumper to that wire, no luck..

took black/white strip wire running to compressor clutch, with jumper wire, wouldn't come on..

running out of ideas here, and my daughter hates the 100 degree temps..)

 

Mine, I tested the clutch wire and it is hot so I bought a new compressor. Will change tomorrow and give an update.

 

changed the compressor today, and everything works fine now.

 

I would look into changing the compressor if I could afford it, but where i'm caught up on also is that there isn't power going to the compressor. hit it with test light and nothing.. bypassed pressure switch still nothing.. I hit the compressor with fused power and it still won't come on, so I'm guessing multiple issues ? any guesses?

 

I don't have the specs off the top of my head, but you are right, it does seem that the pressure is too high on the low side. Did you check the high side? With the compressor off, the pressure should equalize throughout the entire system.

If the pressure is too high, the pressure sensor will command the pcm to not activate the clutch.

Is that a 2-wire pressure sensor, or a 3-wire? does anybody recall?
If it is a 2-wire, you can jum the 2 wires together to see if the compressor engages then, but only for a couple second to be safe.
If it is a 3-wire it is not quite that simple.


I would recommend bringing it to a shop, to recover, vacuum, and recharge the system.

 

it is a 2 wire.. have jumped it with no luck.. and provided power to compressor both.. and no luck

 

low side is high becuase the pressures on both sides are stabilized because the compressor is not running. whenever you get the compressor to kick on you will see the pressure differences. if you dont have any refrigerant in the system alot of times the compressor wont come on. Sounds like you do have refrigerant in there. Run the car and turn the a/c on. gently and carefully tap on the compressor clutch to see if it gets the compressor going. Sometimes the magnetic clutch can get stuck and a simple tap will tell you that you need a new compressor. If that doesnt work check the obvious, fuses, power going to relays, power going to compressor. if there is power going to the compressor and refrigerant levels are good, then chances are your compressor is bad.

 

You jumped wire directly to the compressor and it didnt come on? You need a new compressor then.