Alternator wiring issue

[Luca]

Hi everyone. I have a 73 challenger with a 440. Had an issue come up yesterday. I changed the valve cover gasket and to do so moved the wiring bundle out of the way to get to the cover. The bundled wires are for the alternator and ignition, coil etc. Anyway so I went to start the car after refilling the oil and it half cranked and smoke was coming from the engine bay. I got out and the brown wire and terminal on the ballast resistor and other end on the alternator, coil and bulkhead to ignition were burnt. Charred right off.  I thought maybe when I moved the harness I shorted something. So I took it all apart and rewired the brown wire that goes from ballast resistor to coil +, alternator field, resistor and ignition with new wire and terminals. Go to start the car and nothing happens but it seemed to have shorted again. No burning but they were hot and about to have the insulation melt. However if I disconnect the brown wire at the alternator the car fires right up. Any idea what the issue is? Short in the alternator maybe? Here is the pic of the alternator terminal I'm talking about. The other wires on the alternator battery and voltage regulator are fine.

[dodj]

With factory coloured wiring, brown doesn't get connected to the alternator. Should be blue and green field wires.
Brown from ballast resistor goes to the coil.

[Bullitt-]

hope this helps.. 



this version may be easier & includes electronic ignition

[Luca]

Thanks. Ya that colored diagram with the electronic ignition makes sense. Not sure why the previous owner hooked up this brown wire. So I had three wires coming out of the alternator.  Goin to disconnect it and check the charging voltage and see if it's working

[Luca]

I checked the voltage and alternator is only 11.8 so it's not charging.  Going to check with the regulator disconnected and see if it's that or the alternator.

[Luca]

So I think the alternator is fried. Getting 11.8 v with the regulator disconnected which 8s equal to batter voltage. I also just noticed that aft
er the rewiring my seat belt dash light is on. Which is great but it doesn't turn off lol...the wire that goes to ignition splits and goes to the seat belt interlock

[Bullitt-]

All I had to do to disable seatbelt warning on my '73 was unplug the seat sensors under the seats....

[Chryco Psycho]

The blue wire to the alt is 12v feed , the green wire from the alt goes to the regulator which controls the ground to regulate the charging , if you ground the terminal for the green wire you should have 15v , this is ok to test but don't leave it grounded !!

[dodj]

Not sure why the previous owner hooked up this brown wire. So I had three wires coming out of the alternator. 

You would have to trace it out, but the brown wire may be the wire for the washer pump on the pass side inner fender

[Luca]

Thanks for the tips. My washer fluid container is all cracked...its original  I ordered a new alternator identical replacement from Amazon for 80 bucks. Going to swap it out and see what happens

[Luca]

That brown wire was going from alternator to the ballast resistor and splits to the regulator and ignition. Doesn't make sense

[tparker]

Was it working before or did you just get the car? The car is 50 years old, so it is always good to trace the wires and compare with a wiring manual. Good luck

[dodj]

Was it working before or did you just get the car? The car is 50 years old, so it is always good to trace the wires and compare with a wiring manual. Good luck

You can tell by the wiring connectors that it has been 'rewired' by at least one person.

[Luca]

Ya it was working it was driving it a bit this fall. It's does eventually need a complete rewire but I want to get it in good enough shape to drive this summer. Then do a tear down next year

[Luca]

Well damn it. Put the new alternator in last night with no luck.  Not getting a charge from it. I even tested with just the battery cable connected and it not putting out any juice. So I know ots not the regulator. What am I missing?