Marker Lights / Turn Signal 68 W100

[Stubs68]

Making good progress on my 68 rewire. Wondering if anyone can tell me which wire from original front marker turn signal goes to the running light and which wire is the turn signal? As seen in the attached image. the original marker / turn signal connector has a Yellow wire and a Green / Yellow wire. I am thinking that one goes to the marker (running light) and the other is the turn signal. No power to these yet so cant test. If anyone has knowledge on this topic please reply. Thank you.

[Wildergarten]

the original marker / turn signal connector has a Yellow wire and a Green / Yellow wire. I am thinking that one goes to the marker (running light) and the other is the turn signal.

This is going to be confusing, so please read it carefully. I don't know which plug you are showing. After the headlight switch, there are three plugs in series going to the turn signals, one under the dash, one at the firewall, and a third at the light fixture. The colors you show here are not the same as my factory manual says they should be at ANY corner lamp in the truck, yet that is clearly an OEM style plug that should be coming from either a front fixture or going to the right front fixture (the left side plug going outward has more wires). The only yellow wire that document shows is to the left turn signal going to the left front paired with a "DG" (dark green) wire representing the running lights which is also found at the right front. So my guess is that you are showing me the plug attached to the left front fixture.

At the headlight switch

The easiest way to ring out the system is to make up a jumper feeding 12V to the headlight control plug terminals B1 AND B2 (the other side of the switch). The "P" terminal on the switch supplies 12V to a DG (dark green) wire to the front running lights (what used to be called "Parking lights"). On the front of the truck, this means you'd see a dark green wire on both sides on the front as running lights.

The "R" terminal supplies brown (BN) wire(s for 300+ trucks) to both back Running lights. (The yellow wire coming from the headlight switch plug goes to the dimmer switch, so disregard it in this case.)

Running Lights

This means you'd see a dark green wire on BOTH sides on the front and a brown wire in back on both sides and the license plate light as running lights. In other words, because the colors you show do not correspond to my manual, if there is a wire going to those lights that is the same on both sides, that's the running light wire.

[PwrWgnDrvr]

Making good progress on my 68 rewire. Wondering if anyone can tell me which wire from original front marker turn signal goes to the running light and which wire is the turn signal? As seen in the attached image. the original marker / turn signal connector has a Yellow wire and a Green / Yellow wire. I am thinking that one goes to the marker (running light) and the other is the turn signal. No power to these yet so cant test. If anyone has knowledge on this topic please reply. Thank you.

Interesting pic.....green and yellow wire on one side of the tape, green wire only on the other side.... ...rabbit in the tape trick?

[Stubs68]

Sorry, picture is not showing the complete wire and plug. The plug has a green / yellow wire and a yellow wire. From what I have found the green / yellow is the turn signal and the yellow is the running light.

[Jims68]

According to the 1968 Schematic, BOTH sides use the Dark Green wire, so that would be for the Parking Lights.

The RIGHT side uses Light Green for the Right Turn Signal and the Left side uses YELLOW for the turn signal.

[Wildergarten]

...rabbit in the tape trick?

Yep, it's pretty strange.

[Wildergarten]

According to the 1968 Schematic, BOTH sides use the Dark Green wire, so that would be for the Parking Lights.

Yep, that's what I see.

The RIGHT side uses Light Green for the Right Turn Signal and the Left side uses YELLOW for the turn signal.

That's what it says, but his image has both LG (light green) and YE (yellow) on the same plug, which, (if the harness was made according to the manual) would be impossible. That's why I gave him a way to ring it out to find out what the hell is going on.

[Jims68]

That's what it says, but his image has both LG (light green) and YE (yellow) on the same plug, which, (if the harness was made according to the manual) would be impossible. That's why I gave him a way to ring it out to find out what the hell is going on.

Sorry, I got ahead of myself reading the previous posts...

Unless the "PLUG END" has been replaced at one time. I can't really see the colors BEHIND the tape good enough. A probe type test light would also work just by sticking it into the hole or post end.

Good Luck!

[Stubs68]

Thanks guys. I am out of town this week but when I get back I will check each side to see if the plug wires are different on the drivers side a passenger side. I just assumed the colors would be the same on both but as you mentioned they may have different colors on different sides. Stay tuned.