The Stovebolt Site Forums The Shop Area The Electrical Bay installing door switches to turn on dome light

1952 chevy 3100 truck that I am doing a retromod on.

Can anyone describe how to wire door switches that will turn on the dome light when you open the doors? I would like to have the dome light switch also work so that you could turn the dome light on and off with the doors closed via the switch at the dome lite. The only way I can see to do this is have door switches that will supply power when the doors are opened and then run a wire to the side of the dome light switch that is connected to the bulb thus bypassing the switch when using the door switches. This entails running hot wires from a constant voltage supply to the door switches and then up the A pillar to the dome light.

Any better ideas would be greatly appreciated.

Yes, that's how I did it on my '38.

The single conductor door switches and the headlight switch complete the circuit to ground. Run a single, fused, hot to the lamp assembly. Bring a ground down to an insulated junction. Attach your headlight switch dome circuit and the door plungers to this central junction. You have less wires to run on your truck, but my Suburban required another one from my barn doors.

Not sure I understand. Perhaps you might expand a bit on the actual wiring and electrical path it might help as any to reduce the wiring would be great. My truck never had door plungers and I would like to add them. The dome light gets power from a constant voltage source that feeds to one side of the dome light switch and assembly that is located at the rear wall of the cab near the top. That switch, when flipped supplies power to the light and the light socket supplies ground via the cab and chassis. if I install ground only door plungers there is no power path from the hot side of the cab dome light to the ground switches in the doors. That is the problem that I see. Maybe if I isolated the cab dome light so that it could not ground via the actual body of the light assembly then what you describe would work. Does your dome light assembly have a switch with the hot wire connected to one side of the switch?

Pat

You're basically just running a parallel line with switch in the door pillar. Hot wire comes directly from the battery to the door button then from the door button to the light.

The wiring diagram does show the onboard switch on the hot side of the bulb. It may be possible to move the switch to the ground side of the bulb, which would mean the bulb socket would have to be isolated from ground. Then the door switches could be connected in parallel to the onboard switch. And any switch would provide a ground and turn the light on.
If you somehow isolated the dome light body from ground, then the onboard switch wouldn't work. I think that might be harder to do than isolating just the bulb socket.
Otherwise, leaving the onboard switch as-is, you'd need isolated door switches with two contacts, one from power and the other to the bulb side of the onboard switch. That would mean a switched power wire from each door switch to the dome light to bypass the onboard switch (a total of 3 wires run to the light, one constantly powered to the onboard switch and one each from the door switches.)

On my truck, the dome light is always hot, with the ground wire connection made when the switch is turned on at the headlight switch.
You could run parallel grounds to each door that complete the ground circuit when opened.
The ground wire from the light would be split to run to the switch and both doors.

The 55.2 wiring diagram only shows the headlight switch providing ground for the dome light, so that would be easy to intercept that wire under the dash for grounding door switches. I assume jmoore's 57 is the same.

But the AD trucks (including Patharr's 1952) only have a single hot wire going to the dome light, switched by the onboard switch at the light. So additional wires would have to be run to the dome light, OR the onboard switch left on and isolated 2 terminal door switches wired into the hot feed to the dome light for door switches to work. That would result in ONLY the door switches turning the dome light on, and not the onboard switch.