Joined: 22 Aug 1999
Location: Seattle, WA USA
|Posted: Sat Jul 17, 2004 5:08 pm Post subject: wiring up a brake controller in an X5
|The X5 uses a hall-effect sensor for the brake pedal. Not the normal single connection contact switch.
Here is how to tap into the electronics to get a 12v signal when the brake pedal is pushed, without causing brake light faults.
I just did this today with a new brake controller. What a pain, but it works.
I have a solution now. My controller for reference is a Tekonsha Prodigy. You need power and ground to the unit. I installed it in the ashtray and used power and ground from the cigarette lighter wires. The wire for the trailer brakes is routed under the console, under the rear carpet, and then with the wire looms on the driver's side to the rear. You need a male pin part # 61 13 1 376 193 (<$1) to go into the trailer harness plug.
The difficult connection, as the post says, is the brake light switch connection. I used the center stop light connection from the light control module. The Light Control Module is in the passengers footwell (remove black cover under glovebox and then pop out footwell cover). The center stop light is the black/yellow wire going to pin 10 on connector X12. X12 is the connecter that is the top of the three connectors on the Light Control Module. The Prodigy has a 1mA load on this line (almost nothing). Be sure your controller has a minimal draw on this line before using that output of the LCM.
[ 07-17-2004: Message edited by: dale ]