Measure the voltage on both wires. The one that goes off when the key is either off or out of the ignition is the one you want.
Has anybody had any experience with Install a P1900 in a Chevy Impala? I have a Starter wire(yellow), an Ignition 1 wire(pink), and an Ignition 2 wire(green). Which wire do I connect the yellow ignition wire on the P1900 to? I'm thinking the the pink. Thanks.
Ok...i tested the yellow wire. It is 12v in the on position(not started) and when the car is started it's like 13.9v. Is this what I want?
I hooked everything up and it works great.