Ok - this afternoon the temperature's 85, and with ac on full I found the following -

1. with refrigerant can in warm water, gas transferred to low side ok.

2. initial pressures - low side 10, hi side very low (5-10)

3, on charging, low side went up to 50-60, hi side went up to
about the same; gradually fell back to previous levels.

4. applying 12v+ to either lead on the pressure switch at the drier/receiver, I did not hear a click as the clutch engaged. Of course, to complicate matters, I have a high frequency hearing loss. (Worked in a factor for a while when younger.) Still, I think I should be able to hear it.

Looks like I have some work in store for me....

Does it sound to you that the clutch is bad?

I know I can get an R4 clutch separately from the compressor. How can I test the compressor? If it's bad, I'd just as soon replace both as a unit rather than find out I need to later. One possiblity might be a just a bad clutch coil - if shorted or open I should see it with an ohmmeter.

The PO had this system converted to r134 in Feb 2002, by Glen's Auto in Shrewsbur PA. They replaced the compressor with a rebuilt unit, changed the "accumulator", added the conversion service port fittings, 6 oz of "refrigerant oil." (mineral, ester, or PAG??) Is anyone familiar with their work? Three months later they added additional r134.

What is recommended r134 conversion for this system? Are original hoses ok?

Any thoughts on what I should do next will be apprecated.