Core Support Ground

[pilotXC]

Dumb question, but I misplaced the 3 terminal ground wires that I believe ground the two horns to the core support on my truck (72 with stock body harness) and just want to confirm where they go, and what gauge so I can rebuild it.

[franken]

I could be wrong but I think the horn is grounded by it being bolted to the core support.

[ray_mcavoy]

Yes, the factory horns ground through their mounting brackets bolted to the core support.

Optional dual horn installations did use a 3-terminal jumper wire assembly to plug into the truck's single horn feed wire and distribute power to both horns. To make one of those, you can use the same gauge wire as the existing horn feed wire (usually 12ga). Generic 1/4" blade terminals will work, but for a factory original appearance, you can use Packard/Delphi (now Aptiv) 56-series terminals and plastic connector shells.

[pilotXC]

Thanks for the help... I'm still not clear on where the grounds went. In the image below this bolt is where they were grounded and had 2 wires off that ring terminal, anyone know where they go?

[ray_mcavoy]

You're welcome. I believe the ground wires originally attached to that bolt in your picture were for the driver side headlight and voltage regulator.

The factory wiring diagrams show an 18 gauge black wire coming off the LH headlight socket and going to a 5/16" ring terminal that would attach to that bolt. A second section of 18 gauge black wire (also crimped into that same ring terminal) runs to a smaller ring terminal that screws to the voltage regulator. Unless the ground terminal got pulled out of the LH headlight socket, all this wiring should still be attached to the front light harness.

The RH headlight socket should have a similar ground wire with a ring terminal that attaches to a bolt over on that side of the core support. Although that side won't have the 2nd wire for the voltage regulator. And if you have changed over to an internally regulated alternator, you won't need the ground wire for the regulator on the LH side any more either.

[pilotXC]

Ok, I'll double check the right socket because I do have that. I don't have the regulator anymore so that side of the ground I would not need... Do you happen to have a photo of yours? Thanks.

[ray_mcavoy]

Since you're no longer using the external regulator, you can basically copy the ground wire that's on the right headlight socket ... possibly changing the wire length if necessary to reach the ground bolt location. The stock headlight sockets take Packard/Delphi/Aptiv 59 series female terminals (they look just like the 56 series terminals but are slightly larger).

Sorry, I don't have any pics of mine that show that area and it's currently stored away in a garage that hasn't been plowed or shoveled out all winter ... lots of snow blocking the door.

[Andy4639]

Here is a 68 head light and parking light connectors for both sides. The parking light connector in the 2 picture is the support connector.

[pilotXC]

Thanks for the help, I got it fixed now, much appreciated!!