Automotive Air Conditioning Information Forum

Oh, no question about it. No shop would have dicked around with these minutiae components. They'd have recommended a new compressor with the commensurate hurty quote without batting an eye.

So what was the resistance of the removed coil?

resistance was ...zero.

The old coil was pretty yucky. The epoxy had melted and the resistor was exposed.

btw, the new field coil has a resistance of ~3.7Ω.

So the failed coil was shorted?

One might infer that a shorted field coil would blow an upstream fuse (two 10A fuses feed both "sides" of the field coil relay). But the fuses and relay test good. I don't get how an field coil can (apparently) "burn" without blowing out something else other than itself--maybe field coil innards are designed to fail internally, say, to prevent a fire. Whatever.

In any case, I have a new problem. But it's outside of the scope of this thread. So I started a new thread to document t'shooting it.


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FYI: The overheated field coil shows the imprint on the back side that it overheated the front compressor nose housing which can result in a crispy critter shaft seal that could leak on (1) the outer diameter or (2) under vacuum through the Teflon front lip or (3) the rear elastomer lip seal under positive pressure.
hotrodac

, I'll soak the thing best I can in penetrating oil and let it sit for a while. I need a break anyway. But clearly that clutch plate knows i mean business.

I don't get how an field coil can burn without blowing out something else other than itself--maybe field coil innards are designed to fail internally.