w124 climate control -- no functionality
 

The climate control on my '88 300CE was working perfectly until suddenly it wasn't. Now the fan doesn't come on at all. I checked the #7 fuse and the fusible link on the left front fender and both are intact.

Before the climate control suddenly stopped, I had spent about 15 minutes removing and reinstalling the gauge cluster in order to change a bulb. I know this might be a long shot, but could I have disturbed something behind the gauge cluster which caused the climate control to quit?

Many thanks,

Corvo Gold

When this happens, the first thing to do is to unplug the auxiliary water pump. Just undo the electrical connection. If the pump seizes, it causes the overload protection in the climate control unit to cut power to the whole system. Once the pump is out of circuit, it will come back on if this is the problem.

The W124 and W126 CCU's don't have any sort of "overload protection" built into them. If the pump seizes (I've dealt with 3 of them now), they burn out a transistor on the board. Problem solved.

Since the OP was working in the cluster area, check the main plug on the key switch. There is a dedicated circuit off the main switch for the fan motor. It's possible the wiring got disturbed or disconnected somehow. Otherwise, it's likely coincidental.