My 1999 Jeep Cherokee compressor is engaging and disengaging every 15-20seconds. I hooked a pressure cable up to test the pressure on the low side and with the compressor NOT engaged it reads very high psi BUT when the compressor is engaged it reads zero to low psi. I took a paper clip an put it in the wiring to manually turn on the compressor and it stays on but the psi still reads zero. Do I need freon? Or is the a wiring short? Or is my compressor or clutch bad? Please help it's hot out!! Thanks.

 

What is "very high" (in psi) on the low side, what is the high doing, at what ambient? Have you or anyone you know of used a stop leak product in the A/C system?

 

You got Actually PSI #'s?
Seems like clutch is bad

 

Add a little Freon...

 

It was all the way over in the red part of the gauge. I did actually fix the problem. It took 2cans of freon to fix. The reason why it wasn't reading the psi when the compressor was on was because the freon was practically not there at all haha so the more I added the higher it went up. And then finally my compressor kicked in by its self and now my AC is great! Thanks!

 

24 oz?(!) it must leak like a sieve.

 

I wold have thought so myself but no leaks as far as I can tell right now. I bought the leak sealer 134a freon so I'm not sure if that will help if there is one but lets hope so. If there is a leak then I just need to replace a tube. No?

 

Depends on what/where it's leaking......could be under the dash, in front of the rad or all kinds of places in between those 2.