I am trying to wire the original heater fan switch on my '63 up to the blower on my Classic Auto Air unit. I did some testing and it looks to me like there is output on a two of the terminals at once on the original switch depending on what speed it is on. Of course I don't understand this so can someone help me understand why? Maybe it has something to do with the resistor and how it works. The new unit has a 3 speed blower so I figured it would work but before I destroy something I wanted to ask for enlightenment!