Been searching around the forums here and havnt quite found an answer to the issue I am experiencing at the moment. I just installed an Z120bt in my 2006 mustang gt using a PAC wire harness. All of the features work as they are designed except for the day/night illumination for the display. The instructions included with the PAC wire harness indicate which wire to connect to the orange/white illumination wire on the Pioneer wire harness, and it has been soldered and shrink wrapped, when my headlights are off the display is in day mode and there is no issue, however as soon as I urn my headlights on the display starts quickly flickering between day mode and night mode (most noticeable on the map screen but can be seen on any screen). I was wondering if anyone else had experienced a similar problem??? My headlight switch is faulty (he positive lock/stop for turning the fog lights off/on is broken so anytime the parking lights are on the fog lights are on as well, do you think this fault in the headlight switch could be causing an issue???

Without testing the wire on both sides of the harness, it's hard to say. It almost sounds like you tapped into a PWM dimmer wire.

I had a 2007 mustang which didn't have illumination at the harness, I ran a wire over to the headlight switch.