1989 300E. I have been having climate problems where there is only heat in the car and no cold. I was told that the interior climate sensor at the dome light could be dirty. I looked at it with a flash light and noticed that it looks like it it clogged with alot of dust. How would I clean this sensor and or test it to see if it works. Also how would I remove it from the ceiling of the car?

Thanks

Fab

I've not done this on my W124, but I don't belive the temperature sensor is directly behind that vent. There's a small fan that blows the cabin air down a long tube towards the sensor.

You should be able to vacuum the dust up and place a 1cm x 1cm piece of paper over the vent to see if the fan is working. The fan should be strong enough to hold the paper in place over the vent in the ceiling.

I'm not entirely sure how to check the temperature sensor itself, I think it's location changed over the production run. It may be buried in the dash somewhere.