Alaternator Install Now No Start

I just installed an alternator on my 58 F134, just removed the wiring off the defective 12v genny, nothing else. It had been previously changed to 12v. Ran fine before but just off the battery. Now won't start. Got gas and fire. Lights, starter, and elec. fuel pump work as before. Any ideas ?
It doe's have a (resistor) I think, on the firewall, wire from + on coil to one post another wire from second post to ? I did change the coil from the old 12v to the new one provided with the alternator kit but I do have fire. Repeated pumping of accelerator seemed to cause no flooding, it has been very cold, maybe moisture in float bowl?
Beats me ????
any ideas welcomed ,,,,,
Thanks, John

 

Some coils have the resistor built inside the coil so if you have the one on the firewall also then you have to much ignition voltage drop. If your new coil is for external resistor then you should be good.

 

Thanks Walt, the old coil is printed " 12v, use with primary resistance wire or external resistor, 067 ". I "think" the new one may be internal as it's for a 6-12 conversion.
I did notice when checking the fire it seemed weak. I'll switch the them back out and try that.
Also the alternator is internally regulated and has some type of resistor between it and the coil. It has one wire to battery and another to coil.
Maybe I should bypass the resistor on the firewall with the new coil if it cuts down on ignition voltage ?
I know next to nothing about automotive wiring, I really appreciate the help.

Thanks again,
John

 

Do you have a GM one wire? It sounds like to me you have a GM Three wire? I put a one wire on mine and it has only ONE wire, it goes to the Amp meter, and to the started. I have a 110 amp one wire, so I have a 100 amp, amp meter on it. A GM three wire needs an exciter 12 volt to it, so they go to the coil so when the ignition is on they have power to the exciter. I am sure some one on this site can say it better than I have, but you get the idea, I hope. Good Luck, Rick

 

G M one wire.

 

Should not be a resistor.. A diode more likely. Eliminate run-on when key turned off.

 

Spark at the plugs? Try it with starting fluid? Pull the plugs and see if they are wet?

 

I believe it is because alternators don't charge unless there is an initial power input to magnetize the windings. The coil wire would provide live voltage when the key is on.

Why I like generators.

 

This method is sometimes used when the charge light on the dash is not used.

 

Depends on the alternator. The residual magnetism in the field iron is enough to excite an alternator if it spins fast enough. The one-wire Delco alternators are designed to self-excite easily, compared to other alternators. A 3-wire Delco does have an exciter current that excites the field without relying on the residual magnetism. The exciter wire is also provides for an alternator light, which the one-wire cannot do.

It's possible that the battery connection from the alternator also connects to the ignition switch, providing power for the coil. However, if this were not connected, there would be no spark at any time.

 

Tim, I bet you nailed it.

I think Glenn and I read this the same way, like he powered the coil off the alt.

 

This tells me your not getting fuel through the carb.

 

It's a Delco, has two wires on a plug in on alternator, one to the + side on coil, other to + battery.
I put the old coil back on, it started up & runs fine. Maybe as Walt suggested the extra voltage
drop due to the new coil being internally resisted plus the firewall mounted resister was to weak to
fire the plugs plus the elec fuel pump and starter draw.

Thanks all for the help!
John

 

Glad you got her going.

 

Good deal, glad it working again.