I've been browsing this board for a week now, and what a great site! I think this will be addicting....
I've purchased a '87 560SEL w/ 149K mi about a week ago now, and loving the car (awesome power, good looks, space, etc.). Some minor issues that I'll tackle once I get some time include a bunch of squeaks in the interior, and removal of swirl marks on the exterior, dent extraction, etc.
But one think that I discovered about the car: For the first 2 minutes (give or take a minute) after I start the car, the climate control system seems to have a mind of its own! None of the controls do anything (off position does not turn it off, the temp. dial has no effect on the temp. of the air being blown). For example, this weekend it was nice out here in Cali, but the car insisted on blowing hot air through the defrost vents, no matter what I selected. Also the recirc button and even the seat heater controls don't work.
But after the first 2 minutes, the controls actually work the way they're suppossed to. Off position turns it off, temp. dial works, seat heaters turn on and off, and recirc button works also. I'm totally puzzled by this behavior, but I'm thinking that some of you gurus out there know the answer!