85 w123 AC pressure switch for r134a conversion?
 

Hi,
My 85 300d has been previously converted to r134a. I am in the process of repairing a leak and hope to fill the system soon. Does anyone know which pressure switch part number/style I should order (not going to spend the $$$ on the genuine part)? I have no idea if the switch was swapped when the car was converted originally, so I didnt want to risk replacing it with the same PN that was originally used for r12.
Thanks!

Pressure switch is the same for R12 and R134.

Hmm, interesting - Mine actually has r134a printed on it - but no part number that I found.

the pressure switch makes no difference, it's only there for a low pressure shutout condition, and 134/12 are very similar at the low end.

it's the TEMP switch that needs to be changed to get the aux fan running at a lower temp for 134.

Awesome, thank you.
So: part 000-820-80-10 ?
Also - which temperature rating? Depending on how I search Pelican Parts, I either get one that is unmarked - or one that says 62c - though with the same part number: 000-820-80-10-MY-INT
Sorry for the 20 questions...

Is the pressure switch a failure-prone part? Or should I just stick with the one that's there with a new o-ring?

Not sure the purpose of the low-pressure switching, it mainly just frustrates you when trying to charge the system. I guess they didn't want owners running the AC needlessly if not enough refrigerant to work. The high-pressure cut-off is to protect the AC clutch from slipping and burning up. If you never over-fill the refrigerant and don't live in a real hot place, and don't let your condenser or evaporator get blocked w/ crud, it should never be needed. It didn't help in my 2002 T&C where the clutch slipped on a 108 F day (after I added a little refrigerant and might have pushed it over the edge). It sprayed molten plastic all around the compressor. Most all vehicles have a low/high pressure switch on the AC high-side.