No power at white/black wire for lights

[Gov Junk]

Yes I have studied the schematics so much yesterday that I literally dreamed about them last night, and am sore today from laying under the dash all yesterday too.

On a M1031...no lights (dash, head, tail, blinkers, markers) but the b/o & service toggles were robbed, so replaced the service toggle. Still nothing anywhere. Then realized there is no pwr into the white & white with black stripped wire on the service toggle. What all does that power? Looked several times & cannot follow it back to the fusebox or anywhere else on the schematic.
I am guessing that may be part of the instrument lights...so checked the fuse box & no pwr there on either side of the instrument light fuse; where does that fuse get pwr from (connected to anything else or just within the fuse bx itself)?

There is pwr to the orange feed into the service light switch & out the blk/org into the main headlight switch, but still no headlights...I'm wondering if I have a bad headlight switch or the white wire has somthing to do with that too?

 

[mistaken1]

We need warthog. In the mean time see if this helps. It was colored by unclesam, I combined the two pages.

If you have power into the main headlight switch do you measure power out? If not may very well be a bad switch.

Do not forget the grounds. Technically electrons flow from negative to positive. Without a solid ground (negative) things will not work or will not work correctly.

 

[wallew]

WHAT Mistaken1 said.

but SPECIFICALLY check the ground wire. it's up under the dash on the drivers side wall WAY up under the dash.

it's a three pronged affair (three spades in a row) and there should be ONE ground wire that goes up to that. mine LOOKED good but as soon as I touched it - well it literally fell apart. I traced it back to good wire, spliced in a new wire with a new spade a plugged that in.

I had lights.

OH, do you have a functioning fuel gauge? if not, then definitely check the ground wire

How about a functioning voltmeter? Does the truck run?

we need a bit more info - it's like trying to hit a fly with a shotgun... if we get lucky, then you get a good answer... if not, then we have failed and you go away unhappy... NONE of which we want

 

[Gov Junk]

Mistaken1 - no pwr out the headlight switch. I believe it's new, but that does not mean its not bad.
The ground is good but I'll double check it.
Wallew - no the fuel gauge does not work; I put a new ground on it, at the tank, yesterday but it still doesn't function & wire into cab looks good.
Voltmeter works & truck runs great!
The white wires to & from the service light switch is what's really got me bum-fuzzled

 

[mistaken1]

Mistaken1 - no pwr out the headlight switch. I believe it's new, but that does not mean its not bad.

What happens if you take a wire and jumper around the light switch?

Do you get lights?

 

[Gov Junk]

GOT IT!!!
As much as I hate to admit, it was partly a ground issue. The switch itself was not grounding good through the dash...I found that out accidentally - thank you Lord! Cause when I had the switch pulled out of the dash hole & dangling, I used a jumper ground from the dash multi spade terminal to my switch & it worked fine.
Then also realized that my main light 30amp in fuse box was loose & was sometimes not feeding it all constant power. I put some elec grease on that & bent around on the fuse prongs so now tight.
Thanks for y'alls help...this site is so cool!!!