Locating Cold Side Of Stop Light Switch on 2012 BMW X5

Question:

Which brake light switch wire is the cold side on a 2012 BMW x5d? Also can this connection be made at the brake light itself instead of at the brake light switch?

asked by: Robert A

Expert Reply:

Finding the cold side of the stop light switch on your 2012 BMW X5 will require the use of a circuit tester like the # PTW2993. The wire will be near the brake pedal, and will be the one that only has 12V power when you press on the brakes. We don't have specific information on its location so this is the only way to find it. This is the best location, but a 3rd brake light wire will also work.

One thing worth mentioning is that we have found in the past some X5's can cause brake controller errors due to the stop light switch wiring on the vehicle. The best way to avoid this is to use the Roadmaster Universal Stop Light Switch Kit # RM-751000. You will connect to this switch instead of the factory wire. It also means you won't have to locate the wire in your X5.

expert reply by: Robin H