I have the carb model 5 speed. The AC light comes on in the dash, but the
compressor doesn't turn on. I traced wires and when I checked for power to
the compressor, it ran when the test light probe touched the wire. It also
works by direct power to it. I assume there are relays for it. I also
noticed a switch on the line, assuming it's for low coolant pressure. My
question is, will low coolant prevent the compressor from activating? I
need to switch it over to 134, but don't want to waste time and coolant
until I trace the problem down. My repair manual doesn't mention anything
about this other than taking it to a qualified technician...

Thanks for your help.

John