Dome light wiring

[Marcos]

so I was recently working on my instrument cluster on my 1980 jimmy when I noticed some hacked up wiring in the dash. Thanks to some fellow members on the forum I was able to repair some of the cut wires and regained functionality of my courtesy light https://www.gmsquarebody.com/threads/anyone-know-what-this-is.26672/

While doing so I decided to also repair my dome light which is currently inoperable. I have a small red wire coming down the cab behind my driver seat which goes down the floor and up into the dash and then a dead end wire. From other posts I’m thinking this wire needs to splice into possibly the white wire coming off the door jam switch or maybe the orange wire from the courtesy light? If anyone can advise where this wire goes I’d greatly appreciate it.

Note: this may not be a factory wire I will add pics to help show what I’m talking about

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[Marcos]

so if im reading the wiring diagram correctly the thin red wire in the picture should not belong, instead the orange wire pictured should splice into the white wire coming off the door jam switch?

If this is true I should be able to splice into the white wire coming off the courtesy lamp that plugs directly into the switch? the reason I ask is because I would like to bypass the door jam switches since those wires were cut and removed anyways.

I would prefer to just turn on my courtesy and dome lights with the switch anyways rather then when the door is open

please advise if this would be correct

thank you
marcos

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[82sbshortbed]

I have the same issue. I'll be hoping someone can help with this.

 

[Marcos]

Problem solved. Since I wanted to bypass the door jam switches I ran the white and orange wires along the cab directly to the white and orange of the courtesy lamp. Everything works with the turn of a switch

 

[75gmck25]

IIRC, the white and orange wires at the courtesy lamp under the dash run from the lamp housing over to the driver's side, under the metal carpet plate below the door, and then up to the dome light. An additional white wire is spliced into the white wire under the dash, and runs over to each kick panel, connecting to the door switches. This allows the door switches to ground the circuit and turn the lights on.

Some points to remember when fixing this circuit:
- It is set up to have constant 12 volts power on the orange wire, and the lights are turned on by grounding the white wire. This is the opposite of most other circuits, which are always grounded and the power is switched.
- Due to this design, the under dash lights and and dome light fixtures are electrically isolated/insulated (not grounded). When you install them you need to make sure the terminals and wires do not accidently ground against something.
- If you have an exterior light on the back of the cab, it is also T'd into the dome light circuit, and there is a switch on the door jamb above the point where the upper seat belt guide bolts on. To turn the exterior light on you need to have the dome light turned on (full left on headlight switch), and the door jamb switch has to be turned on.

Bruce

 

[Charlie7985]

I have an issue with the light under the dash not turning off and the dome light not working at all. I have replaced the door jamb switches with no change.