Need help testing heat and a/c control

[jlmerie]

Thanks mrein3. I visually inspected the switch and the plug on the back. I actually have two of each of them. My test came back with the same results both times I tested.(once with each switch and plug). You suggest to only use a volt meter to test the switch. Don't I have to have a 12 volt input source along with whatever voltage regulators might be in front of my switch? Clearly the purpose of the switch is to direct power to the right wires. I am guessing it is the combination of those wires that end up with the voltage measurements you included. Am I missing something here? It sure would not be the first time