I have a 2004 BMW X5. I have a March 2006 Z1. Eventually I plan on getting DucatiBoy's flasher. For now I want to install the unit per the instructions. One area that is giving me an issue is the parking brake.

Pioneer says to attach the light green wire to the positive parking brake wire. My X5 only has a single wire going to the switch and it is a ground wire. What are my options here?

I have attached a diagram of the wiring. As you can see it looks like the positive end is in the dash cluster.

Yes that single wire is what you want to connect to. As far as I know 99.9% of all parking brake switches and sense wires work this way.

Just take the parking brake sense wire from the z1 (light green) and tap into that single wire going to the parking brake.

When the parking brake is applied it will short both the car's wire and the Z1's sense wire to ground. When the parking brake is off, it will let that wire float, it will be electrically like it's not connected to anything.

That's the way it works, that light green wire from the Z1 is only grounded when the parking brake is applied.

If you just add my circuit, all you need to do it make sure the parking brake if off when you start the car.

Yep, it grounds the circuit through the frame of the parking brake assembly to the vehicle. The circuit goes through the instrument cluster so it can light up the parking brake warning light. Positive voltage is introduced into the circuit on the "other side" of the instrument cluster, and since current flows from negative to positive, that single wire would be the positive of the two, even though it shows ground when the brake is apllied.

Thank you that worked.