A/c problem '93/R12, low -side too high

[k3eax]

I need advise / diagnosis on this one! I am able to read only low-side pressure as my manifold gage need an adaptror, which I do not have, to read high-side.

The low-side read 50psi with the compressor operating --- this is too high. The compressor clutch is switched of after about 5-seconds of operation.

I'm looking suggestions from those who have experienced and solved a similar problem.

[davemac2]

Well, you really should get an adaptor to read the high side also to make a proper diagnosis. I think it is a 3/8" adapter, correct? If the low side is too high and the compressor cuts off almost immediately, it could be an overcharged condition or a blockage, but you really need to look at the high side to be sure. The only thing that is going to kill the compressor that fast is the hi pressure switch I think, or if there is a rpm sensor on the compressor and the belt or clutch is slipping. If the pressure is too low, I don't think it woud even allow it to come on.

dave mc