I just replaced my acc servo on my 1979 300sd with an unwired tools acc upgrade. What a difference. It brought the climate control system from 1960's technology to the 21 century.

It is very easy to install (3 hours and 4 beers). It is not cheap,but worth every penny,if you are planning on keeping you old Mercedes for an extend time.

I have no afflialtion with Unwired Tools, I just wanted to pass along my satisifaction with the product.

Augusta