Help - Blower Motor Wiring
The wiring in some of the aftermarket switches is wrong, at least through the 73 model. The added black coming from the switch shouldn't be there at all. The original switch had 4 wires and a unused contact. Somehow the aftermarket decided to place another hot in run wire there.
Orange can go to orange outside the connector if that's easier than wrestling those connector terminals. Either way it doesn't go to black.