I am trying to get my car on the road and was attempting to fire it up the other day. When the ignition is turned to start, the motor turns over and as soon as I release it, the motor dies. I jumped the coil directly from the battery and the engine starts right up and runs fine.

I assume that the starter is getting full votage since it will start. However, in the on/run position, there is no voltage at the coil. Is this a symptom of a bad ignition switch? Is there something else that could be the culprit? I suspect that the new harness (from M&H) may have the wire terminals in the wrong positions for the ignition switch (new switch on rebuilt column).

Thanks.

Bad ballast resistor or resistor wire for the coil. That old style ignition uses a resistor in line with the coil to prevent coil overheating. The coil is wired so that is recieves full battery voltage when cranking and then goes through a resistor when the key is in the run position.

Ben,
What kind of distributor?
I'm assuming a stock setup...seperate coil and distributor.
There are actually TWO wires that power the + side of the coil. A full 12 volt wire that is hot only when cranking the starter (wire runs from starter solenoid) and a second wire...a resistor wire...that is hot only with the ignition at the "ON" position and originates at the fusebox/firewall connection.

Ben,
What kind of distributor?
I'm assuming a stock setup...seperate coil and distributor.
There are actually TWO wires that power the + side of the coil. A full 12 volt wire that is hot only when cranking the starter (wire runs from starter solenoid) and a second wire...a resistor wire...that is hot only with the ignition at the "ON" position and originates at the fusebox/firewall connection.

I've got a Pertronix distributor and coil (looks stock/no points). There is a yellow wire (from starter) to + post on coil and a resistance wire (from fuseblock) on +. Do I even need that resistance wire? Thanks.

My money is on a bad ignition switch. You by-passed the switch when you jumped battery to coil. The coil gets current from the starter when cranking, from switch when running. Bad switch or bad circuit from ign switch to coil.

My money is on a bad ignition switch. You by-passed the switch when you jumped battery to coil. The coil gets current from the starter when cranking, from switch when running. Bad switch or bad circuit from ign switch to coil.
Agree

My money is on a bad ignition switch. You by-passed the switch when you jumped battery to coil. The coil gets current from the starter when cranking, from switch when running. Bad switch or bad circuit from ign switch to coil.

That's my current hyposthesis. I've got a new switch to try next weekend. Thanks guys.

Do your gauges, dash lights, other accessories work with key in run position? Use a meter or test light in fuse block to see if you have power there when key is in run. I think I would make sure before i ripped the column apart to replace the ignition switch. Maybe your resistance wire is shot.

Yes, check it out before you replace anything. You are lacking power to the coil in the RUN position.

Do your gauges, dash lights, other accessories work with key in run position? Use a meter or test light in fuse block to see if you have power there when key is in run. I think I would make sure before i ripped the column apart to replace the ignition switch. Maybe your resistance wire is shot.

My dash lights and turn signals don't work. However, my highbeam and brake warning light work along with my headlights and brake lights. I wonder if the dash lights and turn signals are related to the ignition switch? Or is that a whole separate problem? Would this also explain why my factory tach doesn't work?

You have 12 volts on the resistor wire? Disconnect it from coil (+) while hunting around to keep it from burning the coil.
You have 12 volts to ground on the IGN terminal on the fuseblock? Might have a bad fuse down there.

Ben,

Are you sure you should even have a resistor in the circuit for the Pertoinx unit? The newer ones say to remove that resistor or wire and run 12v directly to the coil.

But is sounds like a bad switch to me also.

Ben,

Are you sure you should even have a resistor in the circuit for the Pertoinx unit? The newer ones say to remove that resistor or wire and run 12v directly to the coil.

But is sounds like a bad switch to me also.

See, I wasn't sure on the necessity of the resistance wire so I guess I will clip that. I'm glad to hear some consesus on the bad ignition switch. I'll try out the new one (as soon as I can) and see what happens.

I'll also take a look see at my fuses.

If you call Pertronix and give them the number off the base of the unit you have they will fax you the instructions. Just had to do that myself.

If it's the one that ends in "CS" it needs no resistor. That's stands for "Cam Sensing". In other words, it has no magnetic ring you had to install.

If you call Pertronix and give them the number off the base of the unit you have they will fax you the instructions. Just had to do that myself.

If it's the one that ends in "CS" it needs no resistor. That's stands for "Cam Sensing". In other words, it has no magnetic ring you had to install.

Do you mean the Pertronix module or the whole distributor? I bought a whole new distributor from Pertronix for it.

I'm pretty sure you don't need a resistor in the ignition supply circuit so I'd give them a call to verify that.

Also the possibility of the coil itself if it is a stand alone unit and not the hei style dist.

Also the possibility of the coil itself if it is a stand alone unit and not the hei style dist.

It's the stand alone style (no HEI) but it's a new coil. I'll give it try with the new ignition switch. I aced the resistance wire and put in a new 12 gauge wire. Hopefully that'll solve the problems.

I had that problem on a truck. Put in new engine and decided to put in the right ignition switch to get rid of the push button. Same thing as yours, would try to start then die. Direct from battery to coil made it run fine when hot wired. It was the ignition switch.

Yeah Ben, I believe both of the Pertronix units for the GM V8 distributor needs or wants a full 12v in both the start and run position of the ignition switch. You were right to replace the resistor wire.

UPDATE:

I replaced the ignition switch and removed the yellow wire from the coil (apparently I didn't need it with an electronic ignition-starter wouldn't disengage) and it runs great! Now on to the electric fans.