Ignition cuts off with key in run position

[j-rho]

Hopefully this sounds familiar to someone here-
Car is a '67 Camaro, just fully restored, including all new wiring harnesses. Car is minimally optioned - non-RS, no heater or radio, etc.

Battery is a big Odyssey PC1200 in the trunk. Something has been causing a drain on the battery that I haven't yet diagnosed. It isn't too bad, so I just switch off the electrical system with a battery disconnect switch when the car is not in use.

Last night I forgot to do that, and this morning the battery was down at 11 volts. I got the car jumped and running but later when I stopped it, couldn't get it restarted, trying for a long time with multiple jump-packs and everything. After the starter and everything cooled off and the battery was externally charged, the car would turn over and fire, but as soon as the key went back off of the "Start" position and go to the "Run" position, the ignition would die. If I held the key in the Start position it would keep running but I didn't want to spin my starter too high. Before this, it had always started and run perfectly.

A friend put a voltmeter on the coil, and saw 12V when the key was in the Start position (starter turning) but not when in the run position.

The car has an aftermarket Mallory distributor and coil. The original power wires for the stock distributor and coil, I have going to the distributor, and the distributor then "feeds" power to the coil.

Of note, this distributor has a circuitboard inside that allows for stuff like a controllable rev limit, and has been repaired once after being shorted out on an engine dyno session.

I then tried supplying 12V directly to the hot side of the coil but that didn't do anything, it probably was a bad thing to do actually.

After doing that I pulled the distributor cap and it smelled like something electrical was toast. When turning over the car, it would no longer spark at all.

So....guesses as to what was the culprit in the "only power to ignition when key is in Start position"? I've been suggested the ignition switch, the coil, the distributor, one guy even though it might have something to do with the horn relay?

Trying to figure out what parts I need to get ordered to make a race next weekend, and I'll only have the day on Friday to work on it. If I get a coil, distributor, and ignition switch, might that be enough?

Thanks!!!

[dontlifttoshift]

No ballast resistor? I have always ran one with any Mallory distributor. I have seen jump starting issues burn up modules before. I don't know which distributor you have but it sounds like this may be the case.

Then you are not wired from the R terminal on the starter to the coil, right?

Does a stock igntion switch send 12 volts from the IGN terminal in start?

[TheJDMan]

It sure sounds like a bad ignition switch to me.

[another69]

Could be a fusible link if you are using stock wiring to the coil

[j-rho]

Replaced ignition switch, coil, and distributor, same behavior. Car starts but dies as soon as the key leaves the Start position. Could it be the lock tumbler? Something else in the electrical system? Everything else seems fine...this is becoming an emergency... :-(

[dontlifttoshift]

It really depends on how it is wired. If you are running a ballast resistor and then feeding 12 volts from the "R" terminal to the ignition then it would run while in start and die when releasing back to ignition. That is if the resistor was bad or faulty wiring from the ignition switch to the resistor or faulty wiring from the ign switch to the distibutor/coil.

[Hotwhilz]

Had the same issue on a truck I replaced the starter on! It was an Delco with three connectors, replaced it with ah hight torque starter with only two connectors, truck would fire only when the starter was engaged! Coudl it be the starter solenoid circuit that got hot and toast?

Maybe something to look into.

If not you could run a twelve 12 volts for the the iggy switch directly to the coil and this should cure. The ballast is a must doing this solution.

Hope this helps!

[shizzy]

Do you have a Ford style remote solenoid or only the GM style on the starter?

[David Pozzi]

With points ignition a volt meter will read zero with key on and points in the closed position. Rolling the starter will cause the meter to pulse. You would see this better with a test light.
A no run condition would indicate a bad primary ignition feed wire. Stock, this wire would be a "Ballast resistor" resistance wire between firewall bulkhead connector & coil + terminal. It shoild have a white braided covering in an original harness. You can test it with a voltmeter by disconnecting the coil end.
Stock systems use a bypass wire from starter "ign" terminal, (the one away from the block) to the coil + terminal. This supplies full battery voltage to the points during starter operation.