51 chevy alternator help

So I converted my car to 12 volts. Hooked up everything the way I think im supposed to. When the car is running. I take one of the cables off the battery and the car dies. So I took a wire and ran it from the posative post off the alternator to the posative post on the battery. Ran it direct basicly. Its still not charging. But when I first started it up It was charging for a couple mins. Now its not doing anything. The car has a 235 straight 6. It is gm alt with the two plug and then the posative post out of the back. Took the wire from the 2 plug and ran it to the post. Then hooked up the stock wire from the generator. Im thinken the alt is just shot. Or could I have fryed somthing??????

 

You have it incorrectly wired. you need a keyed "excite" wire and an in line light bulb (dummy light) to turn it "off" when the key is off.

 

So It wont charge with out wiring up a light bulb to see if its charging????

 

What if I had a gm one wire alt??? Then could O just hook it to the stock generator wire?????

 

Or does that wire just kind of complete the sercit??? and also I understand you diagram now by looking at it. When you say I can hook that to a source of power threw the key. Do I have to have a light?????

 

I put GM 1 wires on all my toys 55 chevy , ford backhoe ... Put a 1 wire on that baby and ride ...

 

You don't need a light, but you do need some kind of resistor (the bulb acts as a resistor) to step down the voltage to the alternator. What you are doing is 'exciting' the alternator field circuit. Alternators do not have permanent magnets like a generator. They need the voltage to create a magnetic field to start the charging action.

 

Thank you guys. I understand now. One more question. Could I have fryed the alt by hooking it up wrong and messing with it tryen to get it to charge??????

 

no you shouldn't of fryed the alt (hopefully) just wouldn't of been charging because there was nothing to excite it as mentioned above

 

I have a coil with a built in resister. Could I wire it to the posative that comes off my coil and goes to my distribuator?????

 

If you have the wire from the positive on the coil going to the distributor you have the coil wired backwards if it is a negative ground system. When you refer to generator wire, are you talking about the switched wire that came to the external regulator? If so that would energize the alt. It might run and charge that way, but probably would not die when you turned the switch off, unless you put a diode in the line. The main reason for wiring through the old idiot light is to excite the alt., and at the same time eliminate the feedback to the switch that keeps it from shutting off.

 

Im sorry the negative goes the the dis.

 

Whats that suppose to mean????

 

HMMMMM so Can I just run that last yellow little wire out of the two plug to the posative on the coil???? and will this do the job im looking for????

 

no that won't work.

run the little yellow wire to one side of a little 12V (not LED) globe and the other side of the globe to an ignition source. (you can tap into a wire coming off the back of your ignition barrel, i have a 51 chev and i did the same thing.)

that way when you turn your ignition on the light will turn on, once you turn the motor over and it starts the little light will turn off letting you know that its charging and if it stops charging the light will come back on.

 

When I turn my key on. Then the posative side of my coil gets juice right? So wouldent it be the came as hooken it to my key it self?????

 

You need to post some pictures , & No dont hook any wires to youre key ... Yes the positive side gets the juce ... Pictures !!!!!

 

Just picture a coil. I thought the key switch was an ignition source.

 

Easier way....hook the excitor wire, (the small one in question) to the accesory side of the ignition switch, that'll excite the alternator to make it charge, but allow the car to shut off without backfeeding. Works for me, no resistor or light bulb needed because when the switch is shut off, the accesory side is separate from the run side of the switch. It works.

 

If your using the stock armature wire you also need to splice the armature and the battery wires together at the old regulater.

 

I did do that. The two fat wires the went to the regulator I connected them togather.

 

I wouldn't hook it right up at the coil only because it earths out through the alt.

 

Why not just use a one wire alternator? The hot wire that originally went to your regulator would go to the alternator.... The regulator and the other two wires that went from it to the generator go under the bench or out back in the old parts pile.

 

To be Honest. This alt im tryen to use is chrome. I really dont have the money right now to spring for one right now. But when I do this one will be going bye bye. Im just tryen to get the car in running and driving condition so I can start on the body.

 

Check out Madelectrical for reasons not to use one wire alt.....

 

NEVER DISCONNECT BATTERY WITH MOTOR RUNNING!!!!!!!!!
With an alternator the voltage will spike and raise hell with electronics.
Go to Radio shack pick up a 1N4002 diode take your small alt wire connect the diode to it and the other end to a switched 12V. start car if it is charging but will not shut off disconnect diode from wire motor will shut down. reinstall diode in opposite direction. restart car when turned off it will stop running.

 

If you hook it to the coil the engine will continue to run when you turn off the ignition switch. The alternator will back feed the coil and keep it running. A diode would allow you to use the coil positive, but it would be easier to use the light.