Hi guys,

I've got a 2000 E430 4-Matic with 45k. Recently my blower has been going nuts. Some days it works fine, other days it jams in the max position regardless of where the setting is on the control panel. And sometimes it is variable going from low to high at will. It is my understanding that the blower is controlled by varying voltage from the regulator. Is it possible that my battery is getting weak and somehow affecting the voltage?? Also, if it is the blower regulator, will I have to replace the blower motor also as I have seen that it is one part on this model? Any advice would be appreciated.

Thanks

Any suggestions?

The blower speed is controlled by a switching ground -- blower is always powered, and the climate control unit signals the switchbox to switch the ground on and off to control the speed. The signal is a variable voltage applied to the switchbox (yellow wire, I believe).

Very likely the ACC computer is goofed up. The switching unit only fails off, so far as I know.

You should also check to make sure the little blower that pulls air across the inside temp sensor is working correctly, otherwise the ACC may be doing strange things with the fan speed attempting to control the temp. On the W124 it's beside the sunroof switch -- should be a small grille. A peice of tissue paper should stay up against it with the ignition on.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks Peter.