Help with early Front Drive Indicator Light wiring (2 Viewers)

[bb67tlc]

So I'm a little stumped... not sure it worked when I took ownership of my '67, but I'm certainly having trouble getting the wiring right on the Front Drive Indicator dash light. There are two Green/yellow stripe wires than come to the bulb location- one is 12 volts, from the fuse box (the 5amp 'meter' circuit), the other goes to the switch on the transfer case. Then the other wire coming out of the switch is White/black stripe. This one, according to the schematic I have says it goes to ground. But the bulb mount itself goes to ground (as it contacts the dashboard), and there's only one wire coming out of it. So the schematic is wrong, and that White/black stripe wire at the switch can't go to ground too- it would have to go to power. But I can't find where it comes out of the wire harness, and white/black stripe is also used for ground on the wiper harness.
Any thoughts?
Thanks

 

[DSRTRDR]

the indicator light grounds to the dash when snapped into its housing

the white/black wire can get grounded anywhere it can touch metal (frame, if close, or body)

 

[bb67tlc]

Thanks for the reply... yes, I get that the bulb grounds to the dash, but only one of the two units (bulb or switch) can go to ground. Do you see how the schematic doesn't make any sense? Well, it makes sense if that's the way the wiring worked, but it's not.

 

[DSRTRDR]

the circuit is completed/activated only when the switch is pushed - that brings power to the indicator light as well

it is completely opposite from domestic vehicle wiring philosophies

 

[65swb45]

The 4wd switch should act as a circuit interrupt. Power constant from fuse, returning wire to bulb, which lights when the switch lets the juice through...provided the bulb has a good ground.

 

[bb67tlc]

Hey Mark- thanks, but you're describing power going to the switch first and then to the bulb and then to ground. That's how I think it should work too. Except the schematic shows power going to the bulb, to the switch and then to ground... but the bulb goes to ground! (there is no second wire out of the bulb to go to the switch). I think I have to find that White/black wire and send power to it.

 

[DSRTRDR]

no power to black/white - that's a ground wire

 

[ToyotaMatt]

So I'm a little stumped... not sure it worked when I took ownership of my '67, but I'm certainly having trouble getting the wiring right on the Front Drive Indicator dash light. There are two Green/yellow stripe wires than come to the bulb location- one is 12 volts, from the fuse box (the 5amp 'meter' circuit), the other goes to the switch on the transfer case. Then the other wire coming out of the switch is White/black stripe. This one, according to the schematic I have says it goes to ground. But the bulb mount itself goes to ground (as it contacts the dashboard), and there's only one wire coming out of it. So the schematic is wrong, and that White/black stripe wire at the switch can't go to ground too- it would have to go to power. But I can't find where it comes out of the wire harness, and white/black stripe is also used for ground on the wiper harness.
Any thoughts?
Thanks

View attachment 1871193 View attachment 1871194

The 4wd switch should act as a circuit interrupt. Power constant from fuse, returning wire to bulb, which lights when the switch lets the juice through...provided the bulb has a good ground.

no power to black/white - that's a ground wire

Take Note the small Lump on the side of @bb67tlc 's socket , That's a broken solder joint for the stand alone green w/ yellow tracer stripe wire that has broke off and fell behind the dash .

here is a same in kind example of as Un-Broken one , it's possible the broken wire is longer in length ?

its Super hard to Solder Copper strand to zinc plated steel , that why these solder joints often fail and look sloppy from the factory

in my Explorations with LED conversions and Polarization , i had to buy a Special Flux online and apply way more heat then usual to solder a

simple joint like this

the example photos are a original toyota unaltered solder joint

 

[bb67tlc]

Well that would make a lot more sense, and the bulb wouldn't be grounded at the fitting in the dash- the ground has to be that white/black wire at the switch, and the schematic is right. I should've looked closer at the fitting. I'll get my little propane torch going... carefully!
Thanks @RAGINGMATT

 

[bb67tlc]

Mission accomplished... found the little wire that had broken off. My faith in schematics has been restored.
Thanks!

 

[ToyotaMatt]

 

[ToyotaMatt]

Mission accomplished... found the little wire that had broken off. My faith in schematics has been restored.
Thanks!

View attachment 1871833

great , glad it worked out to be the de-soldered wire theory i had


But , i noticed u are still using a stone age incandescent bulb


How would u like this Warm Rich green Glow in the cab of your truck at night or day ?

i finally have been able to source a stubby LED dash indicator bulbs in both green and RED

if u want a green one for this particular indicator light , shoot me a PM , i will send u out a Sample

they simply ROCK

 

[ToyotaMatt]

Repair work and upgrades on a recent JOB