Air conditioning problem....1986 420SEL.
 

The last hot day I drove my Mercedes, the airconditioning worked just fine. We had a terrific Alabama super thunderstorm complete with pyrotechnics and when I went to drive the car, the electric windows and windshield wipers would not work. I did not try the A/C. I played with the fuses the next day and got the windows and wipers working and was quite proud of myself. I did not try the air until today. It doesn't work. The compressor clutch does not pull in. I ran a jumper from the fuse box, fuses are ok, and the clutch pulls in. So, I am guessing the clutch is OK. The clutch, however, does not pull in when I try to run the air from the passenger compartment. The fans run etc; but, no clutch, no compressor, no cold air. Does anyone have any suggestions for a logical sequence to trouble shoot the problem. I added some freon to the system in June and it worked just fine. Are there any sensors I should be looking for to assist me in getting this thing to work. It is HOT here now and I need to drive the four seat car. HELP!

Of course try replacing fuse # 5 as it powers the A/C control unit.
There is an OVER HEATING switch imput into the A/C compressor that also can keep the compressor from comming on. TRY unplugging the Green(OR red) 3 pole sensor at the front of the engine & then see if the compressor comes on.

MB DOC (or anybody), I've also got an issue with my A/C..well actually its the blower motor. The fuse (#16) constantly blows and the bottom of the fuse holder has actually melted out and the only way it works is to have a little piece of the blown fuse stuck down in the cavity where the connection would be and then place the fuse on top of it to make a connection to the top pole on the fuse box. This works but it continues to melt as sometimes I can smell the burning in the cabin as I drive when I turn on the a/c.

I have an 86 560 SEL and noticed that after that year MB decided to have the fuse for the blower motor outside of the fusebox independently fused. Was it always an issue with this setup mine has? I have purchased some 12 gauge wire along with a 30 amp fuse line to possibly tie into the blower motor wire eliminating that fuse and running it direct. Is there another way I can do this and if I can just replace THAT part of the fusebox, how does one do this? Better yet, how would I even go about making an independent fuse (the one I purchased is a 30 amp blade type that I feel is more reliable than the ceramic fuses) and access the blower motor's wire going to the #16 fusebox space? So far I just have a crapload of 25 amp ceramic fuses to keep replacing them as they blow every now and then which sucks.

Thanks in advance.