I have a dome light out of an '80 or so Bronco. It has a chrome body with a white lens in the middle with individual map lights on either side of the dome light. The dome light works when I attach it with a screw identical to how the original dome light is attached to the single black wire. The map lights work if I jump the black wire to the other hot contact on the "new" dome light but the map lights work only when the doors are open or the dome light is turned on with the headlight switch. My question is, am I correct in assuming that I can just run an additional hot wire through the A pillar to the map light contact or do I need to provide an additional ground as well? I'm assuming the two lights share a common ground. I think I have it figured out but want to run it by some of you out there who have an abundance of knowledge. I don['t want to find my truck on fire any time soon. Thanks in advance. Lyle

 

Your initial assumption should be correct - run an always-hot (or hot-in-run/acc if you don't want to risk leaving map lights on and running the battery down) wire for that circuit; the ground to the body is sufficient for both. Just be sure to fuse whatever you run, and you shouldn't start a fire.

 

I did something similar when I added a dome light with map lights. I uh... used a chevy astro van dome light...

Look behind the dash for a Brown 2 wire connector (C-702 in wire diagrams) with Black-Blue and Grey-Yellow wires. The Grey-Yellow wire is the one you want to wire to your new upgraded dome light and is protected by Fuse 7 (15Amp Dome, Cargo, Courtesy, Glove & Underhood Lamps).

 

Thanks! Have a great day.