I have an '85 911 and the 2 footwell blowers stopped working after several years of running fine. My main heating blower in the engine compartment runs when either of the heating levers are pulled up. When I turn the center dial which has settings at 1,2, and 3, the footwell blowers do not come on as they have in the past.
My Bentley manual addresses only the automatic heating system for '86 and up. I have a manual heating system.
I seem to recall reading that there is a relay in the engine compartment that is made when the main fan is turned on which allows the footwell blowers to engage when the center dial is turned to one of the 3 positions.
I also found the footwell blower resistor in the luggage compartment on the right side. I tried to take off the 3 contacts to put an ohm meter on them, but quit when they resisted. The resistor looks original and I didn't want to tear it up.
I would appreciate any advice on how to diagnose this issue.
Thanks.
