Im rewiring a 77 f250, Im stuck on the dome light. I have a universal wiring harness. Here is what it says,




This next picture is of the door switch colors are green / yellow and black red maybe? not connected to anything but the switch in the door.



Nest picture is of the pig tail that runs up to the dome light.



I have no idea if the door switch needs to be used in this or not, I can also use the headlight switch to turn the dome on it says once wired.

 

Here are 2 dome light statements from an FTE elec guru. Maybe it will help? Yes it is normal for the headlight switch to rotate (clock wise to dim the dash lights and turned counterclockwise to brighten the dash lights fully AND if turned fully counter clockwise (pass the click) (with the doors closed) turn on the interior dome light.

"For the domelightwire, hot-at-all-times power comes goes to the headlight switch as a GREEN with YELLOW stripe wire. Domelightpower comes back out as a BLACK with BLUE stripe wire. The same color scheme is used at the door jamb switches. BLACK with BLUE stripe runs out to the actual domelight. BLUE with a RED stripe is instrument panel illumination. It comes out of the headlight switch to the fuse box, leaves the fuse box again as the same color and is distributed throughout the dash.

There is no ground connection to the domelightswitches or the headlight switches. These switches switch power, not ground.
1) Make sure you have 12 volts on both sides of the courtesy lamp fuse. This circuit is hot at all times, so it doesn't make a difference what position the key is in. If you have power on only one side, replace the fuse. If you don't have power on either side, then there is other work to do first.
2) Pull the domelightswitches out and remove them. Make sure the terminal for the GREEN with YELLOW stripe wire in the connector has power.
3) Check the domelightswitches for continuity. With the plunger all the way out (switch CLOSED), the switch should be shorted. With the plunger pushed all the way in (switch OPEN), the switch should be open. If not, replace the switch.
4) With power to the switch proven to be good, and the switches proven to be good, the domelightshould lightup. If the domelightdoes not lightup, remove the cover and check for power at the domelight(not the side that's permanently grounded to sheet metal) with the door OPEN. If you have power here, yet the bulb does not lightup, replace the bulb. This will prove out the door-side; if you get to the point that the doors turn the lighton but the headlight switch will not."

 

In stock, the light assembly only gets hot from switch and grounds through a mounting screw

My guess is to connect the ground wire from your harness to the hole in the sheet metal where the dome light assembly grounds with a mounting screw.

You could try just grounding it to metal under the dash.

.

 

Im at a loss on this. So I too the hot wire which comes from the headlight switch and touched it to the yellow green wire from the door switch, it then sent power back out to the black/ blue wire on the door switch.

So I took the black/blue wire from the dorr switch and connected it to the yellow green on that runs up to the dome light and it turned the dome light on and off. But I have no way to turn the light on with the headlight switch if door is closed.

 

Normally, when the light switch **** is turned ...left? all the way, it clicks and turns on the dome light.

 

X2 on when you turn (rotate) the headlight switch know (lights on of off no matter) turn the **** counter clockwise to increase the dash light brightness to full, and then you will hit a bump. Click over it and the interior dome light should come on. Doors closed.

Universal harness might be the issue?

 

I bet Chevy and Ford wire dome lights differently, and I also bet that any universal wiring harness is based on the Chevy method and wiring colors.
If it's Ford wiring colors, then I would expect it to follow Ford guidelines. The problem there is, did Ford always follow the same guidelines!

Good luck. Wiper wiring and dome light wiring are a regular nemesis...

Paul

 

Are you using the stock wires from the headlight switch to the door switches and stock from door switches to dome lamp?

How many wires in your new harness go to the switch in total?

How many are labeled for the dome light?
Did you say one of them is labeled ground?

If one of them is labeled for dome light, see if it is constant hot and then see which wire it should swap for. Green/yellow or blue/ black and tap it in to the dash switch. By reading above it should be green/yellow.

You may not need the ground wire from your new harness.

 

Yep I know, but nothing happens

Yep tired that nothing.

Are you using the stock wires from the headlight switch to the door switches and stock from door switches to dome lamp? No , No im using the new ones that are in the new harness.

How many wires in your new harness go to the switch in total? If your talking headlight switch then there is 8 total,





Two answer your next question there are only two wires and yes one says its a ground wire. 40A is the hot wire and 156 is the ground to dome light wire.





The headlight switch is a standard chevy headlight switch that came with it. And yes I believe this harness to be more towards chevy. ARR

 

Here is the pdf link to the harness Im using .

https://static.speedwaymotors.com/pd...019revised.pdf

 

You may have to search and see what the Chevy wiring looks like since no wires are labeled for door switches.



Here is another diagram from my Haynes manual.
What the pen is marking is what your harness seems to be missing.

Try to piece the 2 diagrams together.

You might have to splice your harness wires into a Ford switch that still has a pig tail of the wires still attached.

 

Here is a diagram with the door switch colors. The very top and very bottom of the diagram has each one. Hope it helps.

 

Here I show I would wire it with a Ford switch that still has stock wires attached.

The two 9's (front and rear park lights) to stock Brown

8a to stock blue/red

10 to stock red/yellow

40 to stock black/ Orange or if 40A is the same wire it looks like in your previous post it feeds the light itself?
In that case run 120 to black/ orange

I wouldn't use 120 straight to battery? or the 156 to ground and you only use one of the front 9 wires anyway.

From the stock wires left, run black/blue and brown/yellow to the door switches.

parts of your instructions mention 40 and then 40A, not sure if those are different wires or not, so it is a little confusing.

I would do temporary splices until you get it all working.

Good luck. It's kinda like getting a pc to run apple software usually a glitch or 2.

 

So iI went digging some more and found this, Looks like Im headed to the store to pickup chevy door jam switches

This is what was said "While I'm on Ford and GM headlight switches, the main difference comes in with the dome light wiring. While GM switches send a ground to turn on the dome light, Ford switches send a hot. That's why GM used self grounding jamb switches and Ford used insulated 2 wire switches.Especially when a guy calls and he has a GM style switch and a Ford one wire dome light and I know it's not going to work together--unless you put in a relay to switch the ground signal from the switch to a hot signal for the dome light, haha! "

Here is the link if you want to see pictures
https://www.jalopyjournal.com/forum/...1120201/page-3