The blower motor was dead. I removed from the car and oiled it hoping it would move more freely by hand. Connected to 12 volt battery source, and it ran at high speed. I hooked up to the blower leads on the car and got high speed fan performance when high speed fan was selected but nothing on low speed although there was voltage present.
The three pin connector on the firewall showed all to be well:
At low speed, the control voltage was a little better than 1V. With the blower on high speed, the control voltage was approx 9V.

- I checked the voltage on the blue and red wires that go into the blower motor and it reads approx 12 volts regardless of whether the ac/heater selected on/off.

My guess is that the blower needs to be replaced. Is there something that I have neglected to check?

Walter
1990 300 E

__________________
Walter Sawczak
1990 300 E
1993 Lincoln Mark VIII
1983 Jaguar XJ6

check the commutator and brushes on the blower.any breaks or dark spots on the commutater mean its worn out.if the brushes are too short they can be replaced

__________________
michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon

I have had blower motor problems myself with my 300E, I replaced the regulator underneath the blower motor mounting bracket. Mine works good now.

__________________
Thanks, Nels
_________________________
86 300E
93 W250 4X4 Cummins Power
72 F250 Highboy
89 S-10 408ci BBC
custom V Four Chopper
77 Peterbilt 352
83 Jeep CJ-5