Last question of the night (I hope); When I got the car it had no AC. The blower had been removed, most of the wiring, and the main wire that goes to the blower is gone. Now, my main question is, I'm sure that the dials operate as reostats, but do they work off of a positive or negative?
I know some blowers/reostats operate off of the idea that as you turn the dial it increases the voltage, hence the fan speeds up. In that case I would need a power wire coming from (I assume) the Thermo King unit under the dash? But from where? And in such case, I assume the ground from the blower would just go to the body?
On others, the blowers/reostats work off of the ground, so that as you turn the dial the ground increases and speeds up the fan. In such a case, there would have to be a ground wire coming from the Thermo King going to the blower (I assume, but from where?), as well as a constant 12v power source when the ignition is in the on position (but from where?).
Right now I have a power wire supplying the Thermo King underdash unit, and then a blue and and orange wire going out through the firewall (which are cut off a few inches after they enter the engine compartment). From trial and error, it looks like the orange supplies the voltage out, and the blue is a return wire back to the unit? Those are the only three wires I can find coming from the under dash unit.
Man, this is a mess without a good wiring schematic!!!