I'm not sure what he means by "reverse" brake signal either.
I do know this though, with the painless kit you need to make sure that when your brakes are not depressed, the switch doesn't make a circuit, and when they are depressed it makes the circuit. The GM brake light switch I used had both options, because it was intended for cruise. Figuring out which way your switch works will tell you whether the switch needs to be activated or deactivated when the pedal is pressed. In my case my brake light switch has the button depressed when the brakes are off, and when the brakes are applied the button on the switch is released.
I hope that helps.
