Hi,

This is for a 1980 300SD, 116 body style.

One day the blower quit working. It works if you set it on defrost. But will not work in any other setting. I replaced the blower motor a little over a year ago and since it works in defrost, I doubt if it is the motor.

So what should my next step be? Is this a problem with the controls on the dash or is this a vacuum problem?

If this is a vacuum problem, I have heard you can buy the whole climate control vacuum system as a harness. Is this a recommended way to go? Or do I just start tracking through the system for leaks?