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I would stop, disconnect the battery and drag-out the multi-meter. Your symptoms suggest something is failing . . . or a short as Ross said. There is a possibility of several difficulties, the puff of smoke, the loss of battery voltage when the headlights are ON, and finally the starter switch. Before anything is powered again a lot of circuits have to be checked. However, assuming the car was OK in the Spring, unless the wiring was worked on during the Summer the probability of something being mis-wired is low.

The puff of smoke could be a short in the ignition switch, or corrosion between the power feed and the GA circuit . . . that would go a long way to explaining the other symptoms. The loss of voltage when the headlight switch is cycled could be the toe switch, but I would let the multi-meter tell me if it's bad. They frequently fail abruptly. A short in 15-WGX, &-BR, or 8-G are possibilities. Keep reading, because I don’t think a short in the head light circuit would make the engine shut-off. Checking the headlight circuit may prove to be a lower priority task.

I’m hung-up on why when the headlights were turned on there was insufficient power/voltage to run the ignition. The circuit starts at the battery, down to the starter, back to the ammeter (1-R), through the ammeter to 2 –RY, and finally 21B-R2W to the ignition switch. Remember that’s exactly the circuit that powers the ignition when the starter motor is engaged (hundreds of amp of draw). I’m not convinced a simple short in the headlight circuit could defeat the ignition . . . given a few minutes before the starter draw didn’t defeat the ignition. I’m thinking you would smell something if the current got that high in the headlight circuit.

I agree with HH56, an intermittent OPEN in the ammeter could cause the problem. In this scenario you’re running on either the battery or the generator. The generator voltage is enough to close the reverse current relay, but the capacity of the generator is low because of low engine speed. If the highlights are turned ON (large deflection of the ammeter into the discharge side) and then the ammeter OPENs . . . game over the 16-20 amps of headlight load exceeds the generator and the voltage take a nosedive (remember you’re disconnected from the battery). The same nosedive would occur if the reverse current relay is open. In this scenario the failure was modeled as an OPEN in the ammeter, but any continuity loss between the battery and ignition switch terminal ‘GA’ would do. I’ve seen battery cables corrode between the copper cable and the connector that attaches to the battery post. Loose or corroded connections fall into the same category, as does the ground strap to the battery.

An intermittent OPEN in the 1-R, 2-RY, 21B-R2W circuit, or an intermittent in the positive cable to the battery would explain a lot of the symptoms . . . that’s where I would start.

Let’s return to the headlight circuit and the introduction of a short circuit. Again, at a very low engine speed (generator ‘off-line’), the normal load of 16-20 amps in the headlight circuit does not defeat the ignition, so the headlight load would have to be high enough to produce a voltage drop of something in the order of 2 + volts in the 1-R, 2-RY circuit. The built-in headlight circuit breaker would not open in time to protect the ignition voltage from falling below the threshold needed to provide spark. In my opinion you would smell something amiss with that amount of over-current.

Dumb question: You said you changed the battery, is the polarity correct? That could be another kettle of fish to fry.

I think you hit the mail on the head! When the headlights come on the AMP meter needle buried itself completely on the discharge side. I checked all the connection on the ignition switch and they are clean with no corrosion. I do feel a short is occurring somehow some where.

So a bit of a update…. I started at the front with my volt meter checking battery cables which checked out. Then checked the carb switch again checked out. Then I contorted myself and began undoing each connection behind the dash whether I felt it needed or not. Cleaned each post, cleaned the nuts and the wire connections. Tried starting the car and success. For now…. Will keep everyone posted and again thanks for all the extremely helpful advice it pointed me in the right direction.

I believe our ammeter is of the magnetic type, meaning the current creates a magnetic field and the pointer reacts to the field against a spring. Very energetic device! They will exhibit an initial ‘over-shoot’ and dance around a bit. Your posting about an indication of a large discharge current might have been the ‘over-shoot’. I use the energetic character as a means to check whether the brake light switch is working. Press on the brake pedal and the ammeter better ‘dance’, if not check the hydraulic switch.

If I have a job under the dash that will likely take some time, I unbolt the entire front seat and reposition it aft. If you feel up to it, you might consider replacing the headlight switch circuit breaker . . . if it’s bright and shiny it’s already been done. They can be changed while the switch is installed, and the modern units fit perfectly. I was sent the attached photos when I had a few questions about the dash wiring. Note the light switch circuit breaker.

Before you re-fire the engine think about the puff of smoke, the loss of voltage when the headlights were turned on, instrument craziness, and finally the lack of starting. Finding an intermittent problem is just about the most difficult job we take-on. You did say the car was re-wired . . . I wonder if that a prudent restoration step or an attempt to solve the same problem.

dp

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Those are some of the best, clearest, and cleanest dash pics I have seen! Thanks so much for sharing they really help in identifying where things belong. I appreciate you sharing!

I hate to admit it, but I don’t recall the source of the photographs. Surely it was this site, and likely one of the ‘usual suspects’, but I’ve drawn a blank. I agree with your comment about the quality and saved all of the images for future reference.

dp