I have a 1989 K1500. I’m wiring for 7pin connector. Issue I have is signal from brake switch to controller. I tied into the white wire under the steering column(12v when brake applied). I verified it has 0V no brake applied, 12V applied. I get a “short” message on the controller. If I supply 12v from a different source for test purposes only it seems to be ok. Can someone tell me where they are getting their 12V in brake applied signal to the controller from? I almost think I need a separate switch and can’t tie into the white wire.