Thanks Cusser.I had it into kwikfit recently who evacuated the system then said they couldn't regas it as it had a leak.I bought an STP EzChill and it was going well and was in the green zone when suddenly the pressure went to zero however a few minutes later it went back suddenly but would not sta...

First guess would be that low refrigerant level is getting the pressure switch to do its protection job, and thus preventing the circuit to the compressor clutch from "closing"/completing. So the center part of the AC compressor doesn't engage or turn. Have a shop look at this, they can ac...

Toddmann wrote:Fixed it. Thanks for response.

Todd - you're supposed to post what was wrong, and what fixed your truck, to help others here !!! We all keep learning.

A/C clutch will not engage. I can jump with a paper clip at A/C clutch relay and clutch engages and A/C blows cold air. You are likely low on refrigerant or your pressure switch is bad. Do not simply jumper the switch and run the unit, except for the test that you did, can damage the system because...

Compressor "off" pressures do not tell much. I see where with compressor engaged, and at high engine rpm, that your highest pressure is 200 psi. I'm in hot Arizona, and all my R134a vehicles typically measure 250-275 psi on the high side. Feel your lines going into and leaving the firewall...

When parked in the sun, remember that seats, dashboard, interior can be alike 140F or more, takes like 15 minutes until the cooling really sets in. Start out with outside air (vent) in because that hot air is COOLER than the interior's air; later switch to recirculate mode.

You were over 100 grams R134a low when it was re-filled. I wonder if you have leaked refrigerant since then.

Also make sure all your cooling fans are operational.

Wow. several weeks to track this down, when a test can be made with a sheet of paper......

Anyway, good find.

After you spray the condenser with a hose and find that the high side drops like a rock, check to see if the fans are turning in the proper rotation. Also see if there is air flow going thru the condenser and radiator. Definitely appears to be a condenser air flow problem. This would not be the fir...

bohica2xo wrote:400 psi is a condenser issue. HEAT is not being removed.

Spray the condenser with water & watch the high side pressure.

Have you tried this? bohica2xo knows his stuff, but cannot be there hands-on, so at least try this and report back to him.