'85 300SLD (yes Diesel) A/C renew/refresh

[ROLLGUY]

Almost a year ago I started the job of renewing/refreshing the A/C on the car New to me '85 SL Diesel-repair and renew thread I had to make a custom mounting bracket so the compressor could tuck in tight to the block, and have room to adjust the belt without hitting the sub-frame. I used one of my Gen III plates, cut and ground away parts of it to make it as tight to the block as possible. Once that was done, I sourced a Parallel Flow Condenser that utilized as much area as possible. It ended up needing a 16X24. I had a dual fan setup from a W124, and that worked out perfect for cooling fan duties.

Fast forward almost a year, and I finally got the time to mount the plate and compressor. Since I had the sub-frame out to notch it for compressor clearance, I replaced the lower control arm bushings, and thereby completing the suspension rebuild that was started almost a year earlier. It was fairly easy to mount the compressor with the entire sub-frame and suspension out of the way. I replaced all the hoses with the liquid line (thin blue hose) being the only exception. I had to make two adapter fittings to go from flare to O ring. All of the new components use O rings. Just yesterday, I completed the installation of all the components and proceeded to vacuum the system, and charge it with R12. I had a problem with the compressor clutch not engaging, so I hotwired the clutch to at least get the proper amount of R12 into the system. This morning I realized that I had the wrong pair of wires hooked up to the pressure switch! I had the wires for the fan temp switch on the pressure switch. Much to my surprise and delight, I connected the proper pair of wires, and the compressor and fans came on (I have a triple fuse/relay for the two fans and compressor clutch)! I now have nice cold air (50 deg F) with the ambient temp of 30 deg C (86 deg F).