Electrical issue

[Steve Nau]

I am nearing the completion of my 56 coupe restoration.
It has been running good and am ready for the trim shop.
i sent the speedo off for repair and the cable was loose under the dash.
I shoved it to the side and backed the car out of the garage and noticed smoke coming out under the dash.
It was the speedo cable shorting out against the ignition switch.
Took out the now ruined cable, charged the battery back up.
Starts and runs good again.
Not sure if any of the above is relevant.

That was two days ago. Since then I have driven it several times with no problem.
Today when I started it the generator light stayed on for awhile but finally went out.
It was running fine so I took it out and it ran fine till I pulled it back into the garage and then it just died.
Now it is dead. The wiper motor works but I have no lights and when I turn on the ignition I get nothing.
I don't see any blown fuses.

Suggestions please on how I track down the problem

[Phil Planck]

Smoke may have been from insulation burning off red wire going to ignition switch. If that melted other insulation from wires in the bundle you will have 6v going places it shouldn't. Inside of sheathed bundle might need work. Hope not.

[Steve Nau]

So just to make this more interesting when I went out this morning everything is working again.
So the issue is intermittent.
How to diagnose?

The wire in the ignition switch that got hot was Black with white stripe going to the 15/54 post. It shows no sign of melted insulation.

[Steve Nau]

I am still trying to figure this out. Yesterday I went for a drive. It was running fine for about five minutes and then suddenly just lost power.
I sat on the side of the road for about 5 minutes and then it started right up after being without power in the interim.
I drove about half a mile and it died again. Same scenario. Waited about five minutes then it started and I made it another half mile back into the garage.

I took apart the ignition switch to see if anything is obvious inside and nothing looks damaged there.

Suggestions on how to track this down are greatly appreciated.

[Thomas Unger]

Steve, had a somewhat similar experience as you (short, smoke, wire). Our issue wasn’t the car stopping but intermittent brake lights, turn indicators. Went back to basics. Verified a good solid ground at the battery (the previous owner put battery ground on top of paint/coating; checked fuse block connects (again previous owner didnt use the right connectors, some were very loos). That took care of the various electrical issues we had (we repaired the wiring of course too)

[Thomas Unger]

Steve, had a somewhat similar experience as you (short, smoke, wire). Our issue wasn’t the car stopping but intermittent brake lights, turn indicators. Went back to basics. Verified a good solid ground at the battery (the previous owner put battery ground on top of paint/coating; checked fuse block connects (again previous owner didnt use the right connectors, some were very loose). That took care of the various electrical issues we had (we repaired the wiring of course too)

[Steve Nau]

It appears this problem was due to a damaged/worn out ignition switch. The good people at YNZ diagnosed it as such after reviewing the history of the problem.
I replaced the switch and so far so good.