1990 300E 2.6
Last night on the drive home from work my A/C would not come on, blew hot for the entire 20 mile drive. When I got home I investigated. AC Compressor turning just fine. I decided to check that dual fan thing in front of radiator. Gave them driver side one a spin and it spun fine. A couple seconds later both of those fans began spinning so I checked in the cabin and it was blowing cold. I assume the fans were not spinning during my drive home and that there is some sensor or something that prevents AC from coming on until those fans are spinning? Or what else might cause this? I've only seen this once so far but the previous owner (a friend) said he occassionally had to give those a spin to make A/C work. Doesn't happen often he said but I'd still rather fix it if its cheap and easy.