I put a single pole single throw toggle switch up stream of the speed control. I drilled a hole near the vent crank handle.
The speed control should then feed the forward reverse switch and the vent position switch (I was a bit surprised how cheesy that part is)
I bought two controls together , one slows the blades a bit slower than the other, but the fans are slightly different vintage also, I didn't look to see if the motors were identical.
I put the speed control potentiometer (speed adjust) thru a stainless fender washer and stuck in the original speed knob hole.
Best mod ever
The speed control should then feed the forward reverse switch and the vent position switch (I was a bit surprised how cheesy that part is)
I bought two controls together , one slows the blades a bit slower than the other, but the fans are slightly different vintage also, I didn't look to see if the motors were identical.
I put the speed control potentiometer (speed adjust) thru a stainless fender washer and stuck in the original speed knob hole.
Best mod ever