I'm needing some advice on which wire do I splice into on the brake switch under the dash. I had a 96 until somebody ran into me and had the factory brake wiring. I have now a 97 but it doesn't have the wiring already there. I tried what the dealer shop told me and the controller made a loud bang and then it smoked. Any advice will be appreciated.

Take a look at this link to see if it helps.

http://www.tekonsha.com/files/BC%20Wiring%20Harness%207854%20Rev.%20A.pdf