Originally Posted by BBShark
I think what you described is right. However you will have only off/high speed. I suppose the C4 controlled fan speed with resistors?
The only easy way to do it, other than that getting into PWM electronics, and that not available in even the later 80's......
as for the color codes of the '68, MY RECOLLECTION is there was just one wire going to the blower motor.....on my '72, so maybe some wiring changes..??
I have a console switch that makes just two speeds outta the blower motor.....pick a speed and wired it in.....