European 98 Mazda 626 2L GF
The AC stopped working recently ( no cooling at all, measured at central vent ). When I turn on the AC the clutch engages and seems to stay engaged. The clutch does NOT seem to be clicking on and off. However there is a rapid ticking noise coming from the compressor at idle. It's very similar to the noise in this video, Ticking AC Compressor.
Checking the tubes to and from the dryer / receiver they both seem to be ambient temp after running the engine at about 1800 rpm for five minutes. The tubes from the evaporator also seem to both be ambient temp. The sight glass in the dryer seems to be clear with no bubbles.
There is a four wire sensor in the dryer / receiver. With the AC off the wires read 14.1v,13.7, 13.7, 0 and with the AC on 14, 0.16, 0.16, 0.
With the clutch seemingly staying engaged and that rapid ticking noise from the compressor plus no cooling I'm guessing the compressor is shot but I'd like to hear from someone with more AC experience than me.