A/C Control

If your AC fan is turning on most likely so is the compressor. Best way to find out is to either get under the car or remove the fire wall cover and have someone turn the key. Of course you must do this is a safe manner. Check also to be sure the ac knob is turned to off position and that it is indeed working.

Strange things happen when the 43-year-old ignition switch contacts wear. Just be very sure that noise is NOT the starter solenoid trying to reactivate! By removing the rear upholstery panel, then the steel firewall access panel and trying your key, the noise location should be immediately obvious.

The Pantera was built as a basic supercar; there are no stock electrical protection circuits in the whole machine, but previous owners may have done about anything imaginable in the wiring.

Is it possible that the A/C is not checking the fluid level and compressor could run dry?
Brgds
Hartwig

If the compressor is truly dry- no lube mixed with the freon- its quite possible to seize a compressor just like an engine run with no oil. This would then either break the drive belt or pop the compressor clutch fuse. There are no oil level sensors or any other protections, and with rotary compressors (not stock) there is no oil sump: all lube is carried in the lines. The stock piston-type compressor does have an oil sump that could have been drained.

Just take the upholstering panel and access door off and look inside while doing the thing that makes the noise. The car can be driven with the panels off if you're careful with your right elbow. It may not be the A/C but you'll never know by guessing.

I have oppened the access door and you were right. The noise comes from the A/C compressor. I share your view not to let the A/C compressor turning without any fluid inside. I will disconnect the power cable of the clutch. Thanks for all your advice.
Hartwig