[ccav]

I recently installed a Boss BCPA8 in my 2007 3.0i.

All went to plan with the exception that if the headlights are on the screen transitions between day time brightness to night time brightness settings. If the dash light level is lowered the screen stays on the day time setting longer (the opposite is true when I increase the dash light brightness setting).

Reviewing the harness there does not appear to be another signal wire. My question is, can I install relay- use the illumination wire as control and tap into the accessory wire as signal wire to the radio. In theory this will work but I also know BMWs are sort of touchy when it comes to electrical loads.

Any feedback on this or an alternate approach would be appreciated. I understand that removing the signal will also work but would like to hold that approach as a last resort.

Thanks