Okay I have some lights I want to automaticly turn on when a door is open, but I also want another switch to turn it on when I am driving. I know this is pretty much the same function as the dome light but I have limited knowledge of this sort of thing. If some one could just give me a few tips where I could tap these light into I would greatly appreciate it.

 

The best way to do that is to have 2 relays...wire one relay up to the dome light and the other relay to the switch and ofcourse both wires coming off of the relay should go to the thing that you want to turn on...DO NOT use the power of the dome light to power what ever it is you are powering...make sure that u only use the dome light power as a "signal" to turn on the relay and the main source of power coming on to the relay is a seprate fused link...
-Zoeb