OK, I've completed building this mental wall and can't think this out. Dome light circuit. Original housing and switch (housing is ground)...single filiment bulb. Two door switches (non grounded) and 12 volts coming from the fuse panel fuse.

My new headlight switch Ron Francis Wiring has a dome light position (full counter clockwise) that grounds the circuit to complete the loop and lights the light.

With my dome light housing grounded this switch will not work (i don't think) I need a wiring diagram that will let me use the grounded housing (expensive) and the headlight switch (expensive) together to make lights on using the position on the headlight switch... the door switches and the switch on the housing (although that seems redundant doesn't it) I guess I could somehow figure out how to isolate the housing from ground but it would take some fabrication work for that.

Ron Francis wiring offers a "reverse dome relay" (also expensive) that they say will cure this problem... but it shouldn't be that hard, right ?? I've just got a mental block on this. All you electrical sparky type folks give me a clue or even better a diagram..

tia
john
John

 

you can do it the way I always have, full power to bulb and switched ground from door switches and headlight switch. Isolate the dome light housing from the cab and run the ground wire to the housing. I just did this in my 41 cadillac and mounted the dome light with plastic screws, the headliner material was the insulator but I was threading into a metal bracket. You can use a wood spacer or anything non conductive to keep the housing off the cab structure.

 

thanks Dave... we got to the same place with different paths... I just had to think harder... I had a serious brain fart

j

 

I did mine like drptop70ss when I re-wired my truck. I never really liked all the 12v switching. It just felt safer to switch with the grounds instead. But I did have to run a 12v wire to the dome light.

 

here is the wire instructions for the kit I installed