Originally Posted by Speedy

Ok small wrinkle (maybe). I wanted a full simulation so I added the dome light to the sim. Everything seemed to work perfect, however when I de-activate the door switch in the sim, the lights continue to illuminate for a few and it looks like current is trying to flow backward through the relay. Eventually the relay turns off and the lights go out. I'm not sure that's even possible never had a situation like this before.

I'm not sure what happens with the LG-B wire when it goes through the combination meter (presumably it goes to ground when one of the doors open) but I'm not sure if there's other circuitry in there preventing backward current flow. Having the dome light ground there as well as the relay seems to be giving the sim some kind of issue. I've tried diodes in various places to see if that solves it, but so far no dice.

A diode may be required at the dome light, but I'd only want to do that as a last resort. I'm trying not to mess with the factory wires anymore than absolutely necessary.
@phattyduck @weekendclimber