The Stovebolt Site Forums The Shop Area The Electrical Bay Ignition coil overheating? No start

Seeking the group wisdom on this one. My 41 Chevy 1/2-ton needs reviving. 216 engine, all original. Ran five years ago. I replaced points, plugs, distributor cap, rotor, oil, fuel pump. Starting off gas can to be sure. New 6 volt battery. I tried with ignition key on and also by jumping directly from battery + to the + side of the ignition coil. It'll crank well, but won't catch. I've tried adjusting the points; the timing seems right. I noticed that the ignition coil seem to get very very hot in a short amount of time --- and only after two or three tries, cranking engine for 10-15 seconds. Is it possible that the distributor has a short, at the negative post? Or somewhere else along the circuit. It's a simple circuit and I can't figure out where. I've tried two ignition cols, one brand new and one that works in the another 6 volt truck. Both have the correct internal resistor. I've measured the rotor and cap, and it's correct for the 216 engine. Any thoughts? I'm one guy in a backyard, and can't test for spark at the plug while cranking engine. Another way? Head scratching like crazy.

Hy Colorado51three-quarter, a couple of thoughts, six volt coils do not require resistors nor should they be equipped with one. Are you sure the distributor is actually turning? The hot coil could indicate that the point circuit is grounded somewhere or the points are closed and the distributor is not turning, hope that helps.

A trick I have when testing spark as a one man operation. Got a timing light? Use you wife's car 12 volt battery or a battery charger. Hook it up, put the plug wire clip on any plug wire. Point the light to where you will be when cranking. That will tell you as least the points are working.

I agree with 3B, you have a short in the point wiring or points not working. Replace the condenser also. Try and get a good condenser. The imports have high failure rates. Case in point....I was work on a 1968 Barracuda with the same problem. Points not opening. Everything looked good so I thought rubbing block was worn out. Replaced points twice with point from my FAPS. No joy. Purchased NOS points from old stock on Internet. Now runs great. Lesson...new off shore points had too short rubbing block.

Thanks for the tips! I cleaned the distributor, got another a new condenser, got another new ignition coil. Reconnected all wires, by-passed the ignition switch. It fired up! The '41 is alive and running strong. I still have a question --- is it normal for the ignition coil to get super hot just by sitting there, engine off, connected to the 6-volt battery (by-passing the ignition switch). I suppose this would make sense, since the coil is not discharging the current it's picking up directly from the battery. Stupid question, but it's probably a no-no to keep the coil directly connected to the battery, even with the engine off --- correct? Or do I still have some short-circuit problem happening here?

In a non running state no power should be applied to the coil. Power should come from ignition switch in start and run position. Coils will get hot enough to burn you in some cases. And you actually have it backward, the coil is passing current from battery to ground. That's what making it hot.

Anytime the points are closed and battery voltage is connected to the coil, current will flow and the coil will heat up. This will also burn out the points in a very short time. Until you get everything sorted out, just install a toggle switch in the wire from the battery to the coil and use it instead of the ignition switch on the dash.
Jerry