Automotive Air Conditioning Information Forum

Tim wrote:Do you lose air volume when it stops cooling. That heat switch on top of the compressor may not be working correctly. But you need to trace down why it is not cycling.

What are the highest pressure you see, normally right before it stops cooling.

Thanks, Tim. I should have mentioned that the low side psi was STEADY at 45- never fluctuated. That also migh be a key to the mystery (?). I keep hoping for a clue to the mystery. High side barely moved either, but it was a little tricky as when I was in the cab I coudnt see the guages. But to answer your question air volume didnt seem to change- just kept blowing at a good rate.

Know what could be causing the engine to shake to badly?

Tim wrote:Do you lose air volume when it stops cooling. That heat switch on top of the compressor may not be working correctly. But you need to trace down why it is not cycling.

What are the highest pressure you see, normally right before it stops cooling.

Man, Tim, youre not goinna believe this but the ac works!!! Geez- took the car for a drive to buy some vegetables, and no problem! Ice cold air, no engine lurching, no nothing!! yahoo!! Figure it out!! This happened to me a while ago with Voyager. Take it for a drive and all works well. Thanks for your support, as I will be back with another ac problem- I own 5 cars!

OK, after a week of decent cold ac, not it quit entirely. Back to the drawing board- it was too good to be true.

Heres what I got just now:

static psi is 110 at about 88 degrees F
Engine on, ac on high, low psi is 0-2psi, High is 200
After engine running for 5 min, low = 5 psi, high 200 still

Rev to about 200 rpm, low = zero , slowly going DOWN to negative 5 (5" mercury vacuum??) huh??!! high psi = 200

Air in cab is about ambient to just slightly cooler, barely noticeable. Suction line in engine bay is very cool to cold to touch, but not ice cold. Do not have a fancy temp apparatus to check temp on that aluminum tube- just my hand, going on experience in the past. Colder at the firewall, at the orfice tube "box", then warmer as it goes to the compressor.

Any ideas, people? Gotta do something soon, too hot here in FL.

Thanks.