245 needs help with A/C.

[detroitbrick]

I have a '91 245. I have an issue with an A/C control that is no longer available. It's the HI-Pressure sensor on the lower right of the condenser. Original part number 3540227 (AKA 6848584) comes up "no gots". Can I jump it out safely or is there a repair or upgrade that works better? I've learned via MVS that may be so, but I haven't seen my brick specifically represented.

I've also learned there is a later version of this part that is still available. It's the '93 version, part number 3540657. The only apparent functional distinction between these two is that the original '91 Pressostat, 3540227, is designed for R12 and the '93 version applies to R134a. Since I'm practically compelled to use R134a why not use the '93 version of the Pressostat, 3540657? Will it thread in place of the original? Or is it time for another approach?

Thanks for helping keep my brick running.

[jimmy57]

The high side line high pressure cutout is not replaced by a pressostat. You can jumper it. It is a switch that opens at 425 psi +/- to stop hose rupture or other problems in the event condenser is not effective due to blockage or fan issues. The 134 sensor will be Acme threads and the R12 will be 1/4 flare. I think some 90-91 740/760/940 also used that compressor interrupt switch.
There are switches for this purpose available: http://www.supplyhouse.com/Johnson-Cont ... IoQAvD_BwE

That is a 300 psi version but I bet that seller has other pressures in that type switch.

[detroitbrick]

I'll jump it out. Since my OP, I've discovered through my local dealership that no version of a 240 H-side Pressostat is available (R12 or R134a) though them. Neither is the condensor, or hard lines. So if someone knows of a reliable source of NOS, great. Thanks MVS and posters!