Technical SUDDEN NO SPARK OVERNIGHT

1947 Dodge WD15, 6 volt positive ground.

I've been having trouble with my throttle linkage and thought I might have a decent fix using magnets....anyway I tried to start the car today and no go. No spark. 6 volts at the key. Ignition coil was custom made and expensive and should be fine but I don't know how to test, plugs look good. Points are fine and a few months new, so is the condensor but I've had those crap out on me before. Any ideas or how to diagnose this issue?

I have no idea what could have happened over night. I ran it for a few minutes yesterday.

Headlights aren't working either, but I think that's because the wires are starting to fall out of the switch. Ugh.

 

do you have voltage at the coil?

 

Do I measuare that by sticking a multimeter probe in the coil and then the other probe to ground? I tried that and didn't get anything. I have the old style coil that "comes out" of the firewall.

 

I'd try checking from the negative terminal of the coil. But that's just me. Good luck!
-Dave

 

I'm not getting any voltage between ground and any of the terminals on the ignition coil. The key is turned on. Not sure what could be going wrong here.

 

You said 6 volts to the key. How about FROM the ignition switch? Np V at the coil simply means juice is not making it from the switch to the coil. Run a jumper from a known hot wire to the coil and try again.

Ben

 

Here's a schematic for a 48 Dodge, I'll take a gamble and assume it's pretty close to yours.

See the "Ignition Lock Switch"? The No 14 red wire from that switch to the - terminal on the coil should show 6 volts when the key is in the "Run" position.

https://www.google.com/search?q=47+...AhUQH6wKHd9AD3cQ9QEIKzAA#imgrc=O-rUX07HqxILYM:

 

You talked about using magnets to repair your throttle linkage. If those magnets are extremely strong and near the ignition coil it might be causing the coil not to function properly.The key to the coil's operation is what happens when the circuit is suddenly broken by the points. The magnetic field of the primary coil collapses rapidly. The secondary coil is engulfed by a powerful and changing magnetic field. This field induces a current in the coils -- a very high-voltage current that is sent to the plugs....Just a thought.

 

Thanks for all the help. Apparently I didn't sufficiently tighten the ignition coil lead wire when I installed the new one. It was loose, which is why my whole ignition system didn't work. After tightening it, started up fine. Magnets didn't mess with the coil. Delivered the truck to the paint/body guy, and ready for a freshen up!

 

^^^^^ This is how a thread is concluded.