modifying the blower control on 97 E320
 

I am trying to help a lady out here with a non operating blower on the car mentioned. To do it right takes a good bit of $$ for parts (MB recommendation). I can take the existing fan out, put 12 volts to it and it blows great. Tried changing the regulator to the one from the W140 and it worked for a day or two.

I'm going to recommend installing a separate controller for the hvac fan.

ebay DC mtr controller

Has anyone ever tried going this route?

You can get a correct aftermarket part on EBay cheaper than that...