'71 heater switch sanity check

[brider]

My heater motor only works on the first "click" or position pull OUT on the heater lever. Is this supposed to be HI or LO?

 

[porkysan]

1st click out is high for the blower, 2nd click is lower speed. Mine makes noise in both positions, but really only moves air in the 1st position - high

 

[3_puppies]

yes it is supposed to be 2 speed, the coil resistor may be burned up or the wires broke off it. It's located on the blower housing in the engine compartment

 

[brider]

OK, that makes sense, because I checked continuity across the resistor, and it's open (broken).

But it also means there are other troubles, because in the HI position, the fan BARELY spins, practically ZERO airflow.

In addition, I checked voltage at the motor with the switch on (haven't figured out how to remove the switch from under the dash yet), and it was only like 10.5 V. Could that be why the motor barely spins?

Why is there such low voltage at the motor?