are you connected to the canister by the firewall? if so, that is the accumalator/low side. reading 100ish psi means the system is not kicking in, make sure the clutch is pulling in. is this reading with the engine on or off?

 

Glenn nailed it. The electrical connection on top of the compressor is a high fail connector. Wiggle it with the a/c on max. If it engages the compressor, that's your problem. I've seen it 100 times. That connection needs to be cleaned, or modified. If you can't clean it, holler at me and I'll explain the mod so to speak.

 

I'm hollering, in case mine stops again. I try my darnest not to lay on it when I'm working on the motor but you know how that goes, LOL!

 

I find that you can't really clean that plug too well. So I remove the red lock that holds the female pins in place. Take about a 3/4" long piece of thin stranded wire. strip it and separate the strands. bend 4 or 6 of them in half. Put half a leg of a strand in the female connector, and the other leg let it hang where the lock rides. You may need 2 or 3 strands per pin. When you push the lock back in, it will lock those strands in each female socket. The strands will take up the slack, and make the connection better. Does that make sense?

 

Glenn and Cody are correct. I had the same problem except mine would work for a bit then quit. Back and forth till it finally quit cooling.
Thanks to Cody I cleaned the plug reassembled it a voila' it works great and has ever since.

Thanks again Cody

edit: Reps sent Cody just because I could.

 

HEY, where's mine Neal? Just kidding, I meant to point out the fact that when the clutch was engaged mine blew REALLY cold air so I assumed the system was full. Going down the road on a hot day you defiantly knew when it quit. When pulling a load its tough to find a spot to pull over it get it working again. I'm even is the habit of checking the clutch engagement activity after laying on it to work on the engine! Good Mod Cody!! I'll try some beans.

 

OK there you go. Beans to you too. LOL
I hope this works for you.