I searched the forum for answers and didn't find any about my problem. In my 97 Z28 the AC was blowing hot air and not cycling the clutch on when I turn on my AC. I went to checkers last night and replaced the relay and my ac was working great. It worked all day today. Went out of the house tonight to run to the store and turned the AC back on and hot air again. The compressor is not kicking on. When I hook the pressure gauge up to the low side it is showing me 100 psi and in the red on my gauge. Any help would be appreciated. Thanks

 

Update. I went back outside and tried it again after posting this and it worked. So I tested the low side with my gauge and it said 45. I am now offically lost

 

And its not working again? WTF

 

LOW pressure gauge: When the reading is between 25 and 40 psi with the A/C running. The system is fully charged and should be cooling normally.

High pressure gauge: When the reading gets up around 200 to 225 psi (R12), or225 to 250 psi (R134a)...

Is the compressor kicking on???

 

Reading on the low side is 45. Reading on the high side is 220. It is working intermittently. When I start the car sometimes the compressor will kick on and run cold air until I shut the car off even driving around. Then I will go to start the car sometimes and the compressor will not kick on. I am at a loss for words. I have been researching the forums and can't find anyone who has had this specific problem of working sometimes and not others

 

It may be the pressure sending switch is bad and giving bad readings to the system. Just a thought.

 

Thanks guys. That is the switch by the low side with the three wires in it?

 

Yes..in the low pressure line near the passenger side shock tower. Good luck with it.

 

So I took the switch out and played around with the wires and what not. cleaned it up a bit. I reinstalled the switch and AC is working like a champ. I cycled the car on an off about 5 times checking each time I started up to see if the compressor would kick on and it worked everytime. Cold air blowing out. Also my service engine soon light was on and the 3rd time I started the car to test the AC my SES light went off and has not come back on since. If it was sending codes and the problem was fixed would it automatically reset the PCM without clearing the codes from a scanner

 

Good deal on the fix. I would not worry about the SES light at this point. The code is stored within the PCM but not as a active one. Congratulations.

 

Thanks to all who helped me keep my cash in my pocket. Its amazing what a 10 dollar relay 3 hours of research and help from fellow guys who were once at the point I was before being given, "The Knowledge". That's what it is about!!!!!!!!!

 

You are more than welcome AFK9...always glad to see a fellow fbodyier do a fix and save the bucks. Enjoy the ride.