Did you find an answer to this? If so can you pass it along. I have a similar question installing a Z1 in a 2003 Chevrolet Suburban. I need direction on how to best connect the Z1 illumination wire. Specifically so that the Z1 night illumination mode works in the following 2 scenarios. First scenario is when the dash lights are turned on "Automatically" (headlight switch in "Auto" position, it is dark outside, and dash lights come on automatically). The second scenario is when the dash lights are turned on "Manually" (headlight switch in "Park" or "Head" position, and dash lights come on).