164 Blower Motor

[David Knapp <D.Knapp@domain.elided>]

I have had what I thought was a seized blower motor in my 91 164 Lusso
(RHD UK version) which I have had some great assistance with details how
to remove replace etc..  I was told about a 40amp fuse behind the
firewall which I found at the weekend but unfortunately this was OK.
Whilst I had my head under the bonnet (hood in the US I believe) I got
hold of the end of the blower spindle and to my amazement it turned with
ease.  This now put a different slant on the problem i.e. motor not
seized I check the voltage to the motor, the two wire that go into the
back of it and had 11.7V which I thought was OK.  I then tried changing
the fan speed setting to see if the voltage altered and it did not.
This brings me to think that there is some other form of control for the
fan speed, a relay or something, that changes the winding the voltages
uses or something.  Does anyone know anything on this or even have a
wiring diagram showing this area of the controls.  I did check the motor
out and it does not appear to be down to earth or anything but would be
grateful if anyone knew what resistance reading I should get through
these two wires.

A bit long winded I know but I would like to explore every avenue to
resolve this problem before I have to result to pulling the A/C unit
out, the only way to actually get to the fan!!

Any further help greatly appreciated.

Regards

David
91 164 Lusso
79 Sud TI

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