I just figured out that my question below is irrelevant. The yellow/black wire on the GEM also seems to control the dome lights on my truck. I would delete my post, but I don't see that option.

Hi. I found in these forums how to cut the yellow/black wire on the GEM to disable the door chime. I plan to add a switch there to be able to shut off the chime when I want to. However, I also have a need to shut off the dome light under the same conditions - key in ignition, driver's side door open. Is that also an easy mod? If so, which wire on the GEM is responsible for the dome light coming on?

Thanks