1961 power to coil

[Rick Crunelle]

1961 vert. When I turn the key to run position, I'm getting 12v to the coil. When I turn it to start it drops to 8v. That is backwards... right? It should be 12v when you start it, then drop to 6-8v when running... so you don't burn the points... right?
I'm going to dig into it, but if anyone has had a similar issue, your input would be appreciated. I'll probably just upgrade to the Pertronix Ignitor and run a constant 12v to the coil anyway, but it would be nice to know why it isn't working right.
Thanks,

[TonyC]

What's the condition of the primary wire, the one that attaches to the points and runs out of the distributor to the "-" terminal on the coil? Those wires do tend to wear out with age, and when they do, they can cause all sorts of ignition issues. And contrary to popular myth (which I once resorted to, admittedly), you cannot just replace it with regular copper wire. Sure, it will work for a little while, but the points will burn up a lot faster. You need a specially-made wire to replace; luckily, you can find hits for new, ready-to-install primary wire on E-bay, where I eventually found mine.

Additionally, there is supposed to be a short ground wire that also attaches to the points, with the other end screwed down onto the inside of the distributor. Is that there, and what condition is it in?

---Tony

[Rick Crunelle]

Hmmm... the primary wire looks to have been replaced, so it is likely a standard copper wire. But that wouldn't explain why I only get 8v to the coil at start but 12v when running (again, that's backwards). I'm guessing that somewhere along the way someone messed with the wiring. Oh, and the ground wire in the distributor is still there and looks good.

To be honest, I haven't had to mess with points in 20+ years. I've updated everything I've owned to electronic. I forgot what a pain it is to adjust the dwell in a Ford. If I remember right, Chevys have a little trap door and you can adjust the dwell on the fly with just an allen wrench...

I've ordered the Pertronix Ignitor and coil and I'm just going to wire it to get 12v. I've used it quite a few times and I've always been happy.

[action]

Actually dwell can be adjusted with cap off and engine cranking.
Connect dwell meter, ground coil wire, remove cap & rotor, loosen points mounting screw partially ..
while cranking engine adjust points with screw driver. Tighten points mounting screw

The OE ignition system is very good for the hobby car. Driven for a few miles a week. And rarely ever during bad weather.
Driving 50+ year old cars on a daily basis, or lots of short trip driving especially during times of very low ambient temps ... electronic ignition may be a better choice.

Action

[action]

Actually dwell can be adjusted with cap off and engine cranking.
Connect dwell meter, ground coil wire, remove cap & rotor, loosen points mounting screw partially ..
while cranking engine adjust points with screw driver. Tighten points mounting screw

The OE ignition system is very good for the hobby car. Driven for a few miles a week. And rarely ever during bad weather.
Driving 50+ year old cars on a daily basis, or lots of short trip driving especially during times of very low ambient temps ... electronic ignition may be a better choice.

Action

[tomo]

With the resister wire, you should get 12 volts to the coil in the run position if the points are open and less when the points are closed.

The low voltage that you get when in the start position could be that the resister wire is used in the start circuit or that the ignition switch start terminal or the bulkhead connector. You can use your voltmeter to isolate by connecting the red lead to the POS terminal of the battery and then using the black lead to probe. You should get readings of 0.1 or less. Any reading higher than that means resistance in the circuit.

[Solid]

Or it could be that the battery is cratering under load during starting and have nothing to do with wiring fun.