change over switch????w115
 

Im trying to get the a/c system going in my 75 240d.....
A/C blower only works if I maunaly ground it....
Any clue on whats up...
Wiring diagram shows a change over switch.. but I cant find it..
Blower resistor maybe??? but fan does not work on High, so
it should not be it....
HELP!!!!:(

Look under the dash (just over the throttle pedal) against the heater/ac unit on the drivers side you will see a push rod that is tied to a vacuum canister and controls the internal a/c vents.
That rod has a metal plate fixed on it and when the vacuum is (off, I think) correct the rod is pulled up by the vacuum actuator and the plate comes off the switch and allows the heater fan to come on and turns off the a/c fan. With the plate engaging the switch the a/c fan should run and not the heater fan.

If I didn't explain it well enough let me know and I can take a photo of the switch and location.

OK,
heres the story.... ITS GONE.... that right, not there!!! just a conector with some jumpers in it.....
I moved the jumpers into the right holes by using wire diagrams and a/c blower WORKS!!!!!!!
Heater does not.... but thats a problem for the fall!;)
Going to take switch off of my parts car and see if it works!!!
Thanks for your help!!
Coffee