Dimmer Question

[GunMetalGrey]

I may sound silly here, but how do you wire a head unit's dimmer wire into the dimmer of the e30 (headlight switch) ? or can you not even do that

[GunMetalGrey]

Anyone?

[M-technik-3]

Factory has a wire that goes to just the illumination circuit of the radio. Does your new radio have a wire for it? Should most new radios due.

[StereoInstaller1]

Gray/red IIRC: check the ETM.