Electrical: What black wire goes where on the light switch on our 1960 Lark V-8 convertible w/auto & p/steering?

[Lucy the Lark]

I have the wiring diagrams, but I can't tell which of the 3 black wires go where on my headlight switch terminals. I have the diagrams, but they are unclear because the terminals on the back end of the switch (behind the dashboard & toward the front of the car) are impossible for me to turn from the 2-D of the schematic to the 3-D of the physical switch. The other colored wires, black w/yellow, green, etc., are clear and easy to connect to the proper terminal.
HELP HELP HELP HELP

[gordr]

Well, my shop manual is AWOL, so I don't have a diagram in front of me, but if all 3 wires are plain black, with no stripe, chances are they are all part of the same circuit. Could be the three terminal on the switch are all interconnected, so that it doesn't matter which one goes where. In other words, the switch is used as a tie point.

Suggestion: first check and see if any of the three wires is "hot" with the ignition off. If not, then they all go to some lamp or group of lamps. If one of them is hot, try connecting it to each of the other two in turn, and see what comes on; if indeed one of the black wires is hot, then one of the others will go to the hot side of the ignition switch, and the other probably to the stop light switch.

With the three black wires disconnected, do any lamps light? If so, it's very unlikely that any of the three is hot. You may be looking at wires for tail lamps and instrument lamps, and maybe parking lamps.

There is probably no harm in simply trying the three possible arrangements for the three black wires. There should be no grounds going to the headlamp switch; all wires going to it will be either hot or can go "hot" at one of the switch settings. Worst possible outcome of mis-wiring it is having the wrong lamps come on.

If I had the wiring diagram in front of me, I'd be more definitive. But that's how I'd proceed, not having one. Three wires the same color, all going to the same switch, odds are real good they all use the switch as a tie point, and are all hot/not hot at the same time. If they had different functionality, they'd have distinctive markings. That's why wires have color codes.

A mirror and a flashlight may be of use.

[Lucy the Lark]

Gord - Thank you.
With the ign switch off, I found one of the three unidentified black wires was hot. Looking up under the dash very carefully, I see it appears to be one gauge wire thicker - which makes some sense that the wire carrying the current to the headlight switch might be somewhat heavier.
Tomorrow, with help of a friend, I'll hook up the hot and see what lights. With a mirror and by carefully dislocating both shoulders, I should be able to just see which black wire goes to the instrument lights, which solves another piece of the puzzle - or there'll be a new satellite passing overhead about 10:00am your time. I'll wave and let you know what happens.
Regards, Tom Roadley - Sarasota, Florida where Lucy's top never goes up

[Lucy the Lark]

Gord, I've re-rebuilt the lighting switch, I'm satisfied it will work. I have touched the hot wire - without any switch - to each of the several wires. I have corrected one headlight short, and tomorrow I will track down the final short, hopefully. At an electrical engineer friend's suggestion, I may simply run a new 16 gauge wire from the lighting switch to the device, bypassing the shorted wire - which will no longer be connected at either end. Thanks for your shove in the right direction.
Regards, Tom Roadley - Sarasota, Florida where Lucy's top never goes up

[Lucy the Lark]

Gord - after finding two shorts and a constantly grounded license plate light and a dead contact point on the headlight switch - all has been put back into working order with the exception of the dead contact. I simply used an unused contact for the clock and cigar lighter light, neither of which I have. All is well in Lucy Land.
Thanks, Tom Roadley - Sarasota, Florida where Lucy's top never goes up