1990 500sl climate control
 

Working on a friends car. After several trips to the shop I think I fixed the A/C leak they couldn't find.....the high pressure shrader valve wasn't screwed in tight!! Now that it is charged and holding pressure he is able to confirm that the A/C is intermittant. Owner is not that mechanically inclined, he thinks it is an electrical problem, had it to the dealer several times when the car was new for similiar problems. I used to have a '91 126, does this car have similiar problems with solder joints breaking in the control panel? Any other known problems areas?