Hello all... well this is my first post so please don't hate me. I've been restoring a 1992 firebird GTA, actually it sat up for a number of years and I finally got it on the road and I've been fixing all the little things that have gone wrong with it.

My problem is this: I recently had the A/C system converted to the R-134 system from its original R-12. As long as I have the blower on full-blast it cools very very well...however when I turn it on any setting lower than that its like it no longer cools. I have no idea why the blower speed has anything to do with weither the air is cool coming out of the vents but I did check to see if the compressor was working while on those settings and it was. This happens on max and normal a/c settings. I can be driving down the road with it cooling fine, turn it one notch below full speed and the air gets considerably warmer and more humid. I did this with the cruise on to be sure it didn't have to do with the RPMs of the motor. As soon as I turn it back all the way up it gets cooler again and works normally. Any ideas whats going on here?

Any help is appreciated, I've searched the forums here for this but either I'm not using the right keywords or maybe this problem really is unique. Thank you.

 

This might sound strange, but try getting a clutch cycle switch specificly made for 134A retrofit. The switch sits on the side of the accumulator, which is the big silver thing on the passenger side of the engine bay. The reason I say this is because R12 runs at a lower psi than 134a does. In order for the 134a to produce the same affect as the 12, the compressor has to stay on longer. All the clutch cycle switch does is send a signal to turn the compressor off and on. With your A/C switch set on norm, the signal is sent to the clutch cycle switch to turn the compressor clutch on will occur less than it would on hi-max setting. This may not be enough time for the 134A to be efficient. With the new clutch cycle switch designed for 134a, it will keep the compressor on longer, thus cooling the car better. You can pick the switch up at any parts store, I know they have it at Advance auto and maybe carquest.

Hope this helps man.

Good Luck

 

Thanks for the info man... i'll give it a try and post up here the results.