New Car (With Issues)

[Skippy]

So far, I've pulled the left rear marker assembly and checked it off the car-result sat. Also realized that the nut I was using to check for continuity to ground is electrically isolated-oops. Since then, found a new ground check point and re-did some troubleshooting. Both rear markers have continuity and ballpark correct resistance. I traced the wires and found both rear markers are supplied by a single wht/grn that runs up the harness along the left rocker. This terminates at pin 11 of the forward of the two 12-pin connectors under the dash. Disconnecting both rear markers and the 12-pin and then checking the wht/grn for continuity to ground comes back as open (good).

Edit: Supplied power to pin 11 on the male (downstream) side. Rear marker lights came on. Checked for power from pin 11 on the female side. No juice. That pin is connected to three wht/grn wires.

2nd Edit: Cut open main wiring harness and traced the three wht/grn wires. They head forward toward the firewall, but it looks like one loops back around the back of the kick panel. It's getting dark, so I'll look at it some more tommorow.

[Mark DiSilvestro]

On the left taillight of my '72 250, the top two terminals of the six-hole plug, connect to both taglights, as well as the white & green positive wire, and the brown ground wire to the left sidemarker. Are your taglights dead as well?

Happy Motoring, Mark

[Skippy]

Tag lights work. The white and green wires don't go to the six pin connector on mine, but the brown ground wire from the marker does. I checked to see what wire was connected to the tag lights and it was a gray one. I couldn't see the tracer, but I suspect it is red.

[Skippy]

So today I did some more. I pulled the left front parking light assembly off and examined the wires going to the front side marker light. The power wire to the actual light fixture is gray with a red tracer, but it's supplied at the parking light assembly with one of the grn/wht wires that I found going forward from under the dash. So, there are three, grn/whts headed forward from the 12-pin connector. What I found is that one of the grn/wht wires comes back into the cab, goes off to the left side behind an interior panel, and shows up again in a small harness that ends up back at the main harness. From here, the grn/wht merges into another harness that seems to head toward the ignition switch.

I can't find the connection where the grn/wht supposedly gets power from the gry/red coming off the switch. Any ideas?

Edit: The wht/grn that comes back into the harness from off to the side is a smaller gauge than the other ones I've been tracing. I'm thinking it's for a completely different circuit.

2nd Edit: I neglected to mention that I also looked for a wht/grn to gry/red junction at the fuse block, and didn't find one.

[Blue 72 250]

Is the additional wire a ground? Then you will not need to chase back to the fuse box, just to verify it has a cood connection to ground.

[Skippy]

After hours of messing around trying to fix it the "right" way, I decided a ghetto rig was in order. One by one, I started cutting the wht/grn wires going toward the firewall. I was pretty certain that one was the power wire and the other two went to the front marker lights. I was right, but as luck would have it, I ended up having to cut all three to find the power wire. I spliced the other two back together. Then I ran a wire from the switch to the stump of the power wire. Once that was done, I had marker lights.

Now I'm just hoping the inspector doesn't give me any flak about the mirror. I know where I can get a replacement for cheap*, but I have to wait for the car to clear legal before I can start pulling parts off it.

*In other words a 72 220 that's in nice cosmetic shape, but doesn't appear to have run in the last several years. Of course, if I'm the one to process it, I will try to start it and get it sold as a builder. However, if it won't start with just a jump, it's a parts donor.