auxillary heating fan wiring question, and the cockpit switch for the heater Options

[brant]

Hey gang...

is my memory on this correct?
does the heather lever/fan switch only have one electrical wire to it?

is that a ground wire or a current flowing wire?
(it must be hot since its identified in the current diagrams)

I'm trying to trouble shoot why my auxillary heater doesn't work and want to understand how that switch works.

when the switch is open/on.. does it send power to the engine compartment and regulator board? how does the switch work if it is only a single wire?

or does it then send a ground signal to the back instead?

thanks for everyone's time
brant