My elderly folks gave me their '86 300E to repair a nonworking A/C
blower motor. I replaced blower control unit in my '92 300TE and
thought it might be the same problem.
- The voltages at the control unit plug (yellow/black - behind the
power steering unit) looked good (I failed to check the 12v red!!!)
- The blower itself was seized but I freed it up and it seemed to run
fine on direct 12V.
- I replaced the blower control unit and the blower did not work.
- I traced the problem to no voltage (red should be 12v) at the
black-red-yellow conrol connector behind the power steering unit.
Any assistance with the source of the red 12v appreciated. The car has
automatic climate control. I considered running 12V fdirect rom the
fuse box but was concerned as the wire became fairly hot.