[BigFatGuy]

This is the panel on the dashboard with 2 lights, the "4x4" button, and the "4x4 low" button.

It's come detached from the dashboard, the 4x4 low switch doesn't seem to be working, and I need to pull the dashboard at some point anyway, so I'm starting the planning to replace this panel with a couple of those fancy "carling" style switches.

This seems to be the wiring diagram for the system, with the switch panel slightly above dead-center.

I'd just like to make sure I'm making good assumptions... that way I can tell if something's not right when I start poking around with my meters.
1: the ignition switch SOURCES the 12v for the 4 indicator lights, and the C5/C4 connections SINK this voltage
2: P3 is the output of the dimmer switch, and lights up the buttons for visibility at night. (I think this bulb might be dead in mine...)
3: the two switches driving wires 781 and 780 are MOMENTARY, N.O. (that's a pure guess)
4: The 5 lights are not used by any logic in the truck to detect when something is turned on or activated? (I understand the transmission uses the current flow to the rear lights to detect when the system is in reverse or braking, so LED replacements can cause issues if they don't flow enough current... don't want to find that issue here by surprise)

Thanks!

 

[BigFatGuy]

I should have said, if anything above doesn't sound sensible, or you know it to be wrong, feel free to make fun of me.

 

[dan1994]

PM sent, I’ll try and follow up on this thread after work when I can look at the shop wiring diagram!

 

[dan1994]

So I may be wrong, but I’ll attach some of the diagrams from the Ford 94 bronco/f-series manual so you can look it over too.

1. I think your assumption is correct, it looks like the ignition will supply 12V to the switch in “start” or “run” through the R/Y wire; additionally it looks like the instrument lights receive power in parallel when the head lamp is on or in park through the LB/R wire (dimmed by headlight control).

2. You’re on the money! You should be able to test this in park.

3. This one I’m not so sure about technical terminology (might be a three way momentary), but regardless it looks like a three way switch in the normally closed position. grounding W/LB for “off”(normal); dark blue for 4x4; and O/LB for low range.

4. Without spending too much time, I would agree with you but advise a second opinion.
At first glance it looks like all of the bulbs in the diagram operate similarly... that is after the correct switch is pushed and path to ground established then the bulb turns on.

Attaching images in no particular order.
Let me know if you want to see other diagram sections.

I’m interested in your carling switch swap so let us know how it works out!

-Dan

 

[TomR]

Following the post. Nothing to add to assumptions, just asking for advice on how you reach and remove the 4x4 switch screws behind the dashboard panel. Consider buying new clips for dashboard, mine not right after first time removing them. My experience is the wiring harness doesn’t allow slack to reach these screws. I assume uncliping the harness from the 4x4 switch is the way to go. Appreciate your advice on how you accomplish it.

 

[dan1994]

So for me, I’ve had better luck disconnecting the switch before unscrewing it from the bezel; sometimes those old harness connections can be difficult which makes me afraid to do this on mine too many times.

one alternative might be to use a 1/4” ratchet with a Phillips bit?

I’d dig around and maybe see how others do it without damage to the bezel.

maybe another FSB’er has other input.

 

[BigFatGuy]

From what I've seen on youtube videos, you have to pull the wire connectors off to get any workable distance on the backside of the panel... and, if you are somewhat meat-fisted as I am, you'll need to ask a tiny friend to do it for you.