Does anyone know if this applies to the w124??
removing inner loiner of glove box and the lower passenger trim panel, you can get to the diaphram and lever/actuator. As a quick fix, you might be able to secure it in an open position by wedging some rubber in there. Worked for me, but this was on a W126 body car.
1987 mercedes 300E
1995 e320 conversion(hated the 300e grill)
Monochromatic Paint (Custom Blue)
Flat Badged (front)
custom "carbon fiber" console
18 inch HP EVO rims
Sold! Now I drive a Monte Carlo SS