Having a fleet of older vehicles means my shop sees a lot of concerns that arise simply out of age. This 1996 Ford F250 arrived on this day for an a/c inop concern. Service writer Wendel told me that the compressor was making a lot of noise.

The first step in ANY repair process is to verify the concern. I started the truck and turned on the a/c in the parking lot. As expected, the system blew warm air and made a bunch of noise. With my concern verified, I made my way into the shop, turning the a/c switch to "off" first. That's when the fun began.

When I turned the a/c off, I immediately heard a very loud "clang" noise, like that of an impact of some kind. Turning the system back on again then resulted in no noise of any kind. My suspicions were confirmed once I opened the hood.

Where's the a/c compressor clutch ?

Oh, there it is, laying on the frame rail next to the steering gearbox.

The a/c compressor shaft picked that very moment, (when I turned the system on, then off again). to fail. The rotating inertia sent the clutch flying under the hood.

The compressor shaft actually failed and broke. So this compressor was done. One new compressor, accumulator, and orifice later, this truck was back on the road.