I am trying to wire in the parking brake bypass. I order the microbypass and will put that in when it gets here, but I want to see it work at least in the meantime.
I understand that I need to connect the power side of a switch to the light green wire from the radio. I have built in switches in my truck, so I took power from it to the light green wire. Nothing happened. I verified there was power to the wire but nothing happened.
So I tried grounding the light green wire and it worked. Why would it work with ground and not power?

