I have a similar problem with my 560SL - 1987. The AC only comes out the defroster and side vents. You mentioned that this is some type of default mode. The compressor seems to take a little long to turn on also. Eventually, pushing the control buttons randomly gets that part working. I also do not have the maintenance CD. Any guidance would be appreciated. This is more of an annoyance than anything else! Thanks a lot.
Originally posted by Tim Mabry
I'm trying to figure out a 1986 560SL that has 2 A/C problems. #1. The climate control comes and goes after hitting bumps. When it works there is power at both sides of the fuse (#6). When it quits there is 0 volts at the fuse. So, whatever powers up the fuse has a problem. A bad connection or relay or whatever. Note: The fuse is good. Unfortunately I don't have a manual for this car, just my SEL. #2. (Probably related to #1) When I say the climate control is working, I mean air is blowing out the defrost and side vents only. I understand this is a default mode and means the climate control has a problem. Only rarely does the compressor engage and when it does there are bubbles in the sight glass. I tried adding freon but I'm unable to get the compressor to engage even though I jump the low pressure switch. Reading other threads I'd guess a bad control panel, but I'd like some input from someone with more MB experience than myself. Thanks.