Adjusting the A/C Cycle Switch on a G Body Monte Carlo SS

[vintageracer]

The A/C pressure cycling switches are adjustable on GM cars. Could someone please tell me which direction to turn the pressure adjusting screw on a GM A/C cycling switch and how far to turn the adjusting screw to adjust the switch to cycle properly when using 134A coolant instead of the original R12? This switch is on a G body 1985 Monte Carlo SS.

I look foward to hearing from you!

[MonzaRacer]

Dont simply go to junk yard and swipe newer units, and I have never heard of them being adjustable and I do conversions all the time.
I actually prefer the truck models from early 90s.
Another thing is if this is stock system converted remember use ester oil in systems that have had old r12 mineral oil in them or ROC oil from Cliplight.
But if its all new never used parts use PAG 150 in GM compressor unless you can find info from manufacturer on a different viscosity.
I do have a list at work on recommended oils for specific compressors if you need help on that.
Oh and the drop in kits, are a joke andwill trash a system, it may run but if it ever stops or breaks and is contaminated the next shop will charge big bucks to dispose of the mix and fix system.

[vintageracer]

Look in the back of the older cycle switch and there is a screw for adjustment. Probably not the best way but you can change the pressure level to activate the switch.

I have not been able to go to Pull A Part to get a 134 cycle switch. That's what I usually do. All the 134 switches I have are for Fords.

[Rhino]

When I was doing the work on my Avalanche, I picked up a cycle switch for $12. It may prove worthwhile to just pick up a new one.

[vintageracer]

A new GM 134A specific cycle switch will not screw on the fitting on an accumulator fitted to a car originally using R12.

That's why I want to adjust the original switch set point.