AC fuse keeps blowing on 93.5 v12 : AC clutch or?

The diode is connected in parallel with the coil, you have to disconnect it from the coil to measure it.
The coil is 4 Ohms or about, not far from a dead short, and bipolar, so however you measure the assembly the multi-meter will be always seeing the coil, there might be some variation, but I think not conclusive.

Aristides

yes the diode is in parallel with the coil, but hidden somewhere in the loom,
as per the electrics schematics posted earlier

I’ve got several multimeters, and most have a diode mode, where the value shown is 1 (infinite) or some voltage around 0.6V (or 600mV), which is the diode threshold voltage
I tried using a milliohmmeter, and it was confused by the dioded in the wiring
I didn’t have time to do the same measurement again, but with the coil out of the loom : I’m almost sure the reading will show if the diode is ok or not (the original one , in the loom)

the “free wheeling diode” won’t get much current, as the voltage spike is short : 1N4007 should be fine (or I hope so)

sorry for the delay before coming back : as I had to take the radiator upper cross member to change the clutch, I took the opportunity to get the radiator out and have it checked

It’s back and fitted, so I started refitting everything back together during the previous weekends

The air cond compressor clutch now works, no more blown fuse, and I get some cold

It took a while to get the parts, but the job isn’t too bad, and saved a compressor replacement (and circuit purge and refill)