Hello,

I am reposting this from mbworld primarily because I read threads with responses from M.B.DOC that indicates to me that he might be able to diagnose my problem through cyberspace. I had the aux fan resistor fail in my 85' due to bad bearings on the fan on July 4th of last year, at a gas station where I went to get my propane tank for the B.B.Q. refilled, (They allways go empty on the 4th) well I pulled in and all of a sudden there was an acrid smell through the vents and then smoke coming from under the hood. I shut it down and lifted the hood and there was a nice little fire in the left primary firewall area. The water and air were 75 feet away and cost a quarter which I didn't have on me. The squeegee for windshields however was only 20 feet away. They actually hold quite a bit of water. 4 trips back and forth with the squeegee were able to extinguish the burning leaves where the resistor had failed. The 91' has a cage around it but make sure you keep it cleaned of inflammables. I believe the lack of aux fans should not stop the compressor from engaging; that should be done with one of the temp switches. And that is why I am so perplexed. The mbworld post follows: I recently bought a 1991 560SEL with 112,000 miles to replace my 1985 500SEL with 277,000 miles which was sideswiped and totalled. The A/C blew really cold, (It is still R-12). About a week later when I was changing plug wires, I happened to spin the two aux fan blades. The drivers side was bad and I meant to pull the fuse out until I could replace it. Needless to say I bought a new aux fan but forgot to pull the fuse. A week later my A/C stopped functioning. All functions on the dash unit work, but the compressor won't engage. I'm pretty sure that the caged aux fan resistor deep in the drivers side primary firewall below the fusebox blew, but I would like to get input on this. There seem to be about 5 separate sensors or switches on the motor that are tied into the A/C system. I'm looking for the most logical and easiest fix since temps have been over 100 degrees the last few days and Summer is on its way.

Thank you in advance for any help with my problem.

My AC stopped working today as well. As above, all the controls seem to function, fuses look good and were replaced for good measure in the fuse box. The clutch will not engage though. THis has been checked with the climate control switched to MAX cold as well...nothing. Any help is appreciated.

91 560 SEL 68000 mi

Cheers,

__________________
Michael
Elk, WA
91 560 SEL
(other fine brands from Germany too)

If all of the working fluid has leaked out or if it drops below a certain point there is a low pressure switch that will stop the compressor from engaging. This is to stop the compressor from being damaged from lack of lubrication. This is fairly easy to test for - if the switch is grounded, you don't have enough R12/R134a/whatever. Mine is located on the receiver drier.

__________________
86 560SL
With homebrew first gear start!
85 380SL
Daily Driver Project

http://juliepalooza.8m.com/sl/mercedes.htm