72 battery cable connection

[Robert Bergstrom]

Is this the correct battery connection layout for a 72 350 engine with A/C? The reason I ask is when I hook up the battery cables and plug in the horn it goes off and does not stop until unplugged. Also when I plug it back it does not sound but when the small cable by the fusible link is moved it makes the horn sound off again. I think I have a wire misplaced.

[ray_mcavoy]

Yes, that wiring appears to be hooked up correctly. The small black wire with the rubber inline fuse holder is part of the battery gauge circuit.

That red wire from the positive battery terminal (and fusible link) do supply power to the horn relay. But they don't have anything to do with triggering the relay. For that, there should be black wire inside the cab / under-dash harness that runs from a terminal on the horn relay up through the steering column to the horn button. If that wire is accidentally shorted to ground anywhere along it's length, or the horn button is sticking, it could be keeping the horn relay activated all the time, which in turn feeds power to the horn all the time. Or it could be that the horn relay contacts are getting stuck and continuously powering the horn. Moving or wiggling the wires near the battery shouldn't cause anything to change, unless maybe there is a loose connection there that is momentarily interrupting power to the horn relay and allowing it to release (assuming the relay getting stuck sometimes is what's causing the horn to sound when it shouldn't).

[Robert Bergstrom]

Thanks. I went back and looked at the steering column connection and I had wired it wrong. I am adding some extras to a stock fuse box so I ordered a 4Way 12V/24V Auto Car Power Distribution Blade Fuse Holder Box Block Panel Board. I am adding power windows and keyless entry. I am also adding an Intellitronic gauge instrument panel so am doing those wiring changes. I am learning as I go along which I do not like but have to do.

[Greasey Harley]

Originally Posted by ray_mcavoy

Yes, that wiring appears to be hooked up correctly. The small black wire with the rubber inline fuse holder is part of the battery gauge circuit.

....

Little thread hijack here:
Anyone know what the identical rubber inline fuse on the drivers side is?

[ray_mcavoy]

Originally Posted by Greasey Harley

Little thread hijack here:
Anyone know what the identical rubber inline fuse on the drivers side is?

That's the other half of the battery gauge circuit. Both sides of the gauge wiring are fused where they tie into the rest of the truck's wiring.

[Greasey Harley]

Originally Posted by ray_mcavoy

...The small black wire with the rubber inline fuse holder is part of the battery gauge circuit. ...

Originally Posted by Greasey Harley

...Anyone know what the identical rubber inline fuse on the drivers side is?

Originally Posted by ray_mcavoy

That's the other half of the battery gauge circuit. Both sides of the gauge wiring are fused where they tie into the rest of the truck's wiring.

Excelent! I've been meaning to look that up, now I don't have to. Thanks.

[68 P.O.S.]

Wiring looks correct. I can't tell from the pics, is there a fusible link connected to the power wire that connects to the junction block? If not, you need one. Also, the smaller negative battery cable is supposed to connect to the core support to provide a ground there as well.