| A quick update - and it narrows down the problem, though I'm still thinking about how to solve it. Found a local a/c technician who had all the gauges, kit and fittings to test an R12 system. And guess what - virtually no refrigerant. So that (rather than an electrical fault) was the reason the compressor clutch wasn't engaging.
Did a pressure test with nitrogen, which confirmed there was a TINY leak somewhere (the pressure dropped very very slowly, so it must be like a pinhole or smaller). Impossible to see or hear it.
Now I'm stuck.. The logical further test would be to recharge the system and add some dye and - maybe after a few days or a week - the dye would reveal the site of the leak. But here in UK it's impossible to get R12 even to recharge for such a test. So I seem to have no option but to convert to R134a (drain compressor, get new drier, hose fittings, seals etc). Yet it seems foolish to do that without finding and solving the leak - especially if it's a hose or hose-joint - first. Catch 22! |