I finally got the original A/C on my body-off restored M997 ambulance running.
When I got the ambulance top, the freon lines were open, and insects had nested in them. Also, the engine-mounted compressor, the hoses and part of the wiring were missing. A very BIG Thank You to fellow Steelsoldier Harleyrdr71 for providing me with an original compressor, and some other parts.
I disassembled the whole A/C system, flushed it thorougly, changed the 35 years old seals on the compressor, and swapped all O-rings for a changeover to R134 (Freon = R12 is very much VERBOTEN overhere for years). The A/C oil was changed to PAG oil compatible with R134.
A few days ago I took the M997 for a first, nicely air-conditioned ride:
The Humvee rightaway started to mark its territory with some condensate water:
Here´s an engine room view with the extra V-belt for the compressor:
Restoring the 35+ years old A/C to running condition was an interesting learning experience for me. In my business, I´m daily working with A/C systems, but when a system is broken, we usually just trash them. Being forced to revive an historic A/C system with all-original parts was something new and exciting.