I went strart my 72 newport an when i turned over the key the charging wire wire from the altenator with the fuseable link burned in half i tried changing the srarter relay, but nothing we reconnected the wire turned the key on and hotwired it it started right up i have power everything works but once i turn it off and try to start it with the ignition the wire burns in half again and i have no power to anything. why could this be??

 

Starter wire is shorted to ground or the little wire from the solenoid to the starter motor is Shorted to ground. ( Braided bare wire) Or possibly the starter itself..unhook the starter a turn the key to start if it burns off again it is in the wiring to the starter...If not it is something in the starter...Bill

 

yep, agreed. take your time and trace the power wires on that bad boy.

 

EDIT.............not clear to me, "charging wire" are you actually talking about the BLACK alternator wire, or the RED battery feed into the bulkhead? If RED, I agree a "good chance" is starter solenoid / wire problems
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First question is, "do you have a service manual?"

Go here and download one, there's a link to a 72

http://www.forabodiesonly.com/mopar/...p?p=1970088617

Next, go here

http://www.madelectrical.com/electrical-tech.shtml

and read this article CAREFULLY

http://www.madelectrical.com/electri...p-gauges.shtml

Even if you don't do this mod, the article carries a lot of info on how the main power distribution in these girls works, and their problems. Down the page is the diagram below:

The main power comes off the battery.....to the starter relay....through fuse link....through bulkhead....to and through ammeter..... and branches off in the factory "welded splice" to several places, headlight switch, ignition switch, hot fuse panel buss, then continues on (black wire) back out through the bulkhead to the alternator

Weak points are the bulkhead connector, ammeter connections, in rare cases the welded splice.

One possible cause might be bad diodes in the alternator. If just one diode shorts, or if something happens IE debri, broken winding, nut, bolt, etc gets "into" the alternator, this can short the big output stud, and will blow the fuse link, AND may burn up the harness.

An intermittent is VERY difficult to troubleshoot, unless you "catch" it hot or smoking, etc.

One useful trick is to disconnect battery ground, and wire a lamp in series from engine or body to the battery NEG. This creates protection. The heavier the lamp, the better, to start out with. I have an old stop / tail lamp socket I use for this. When the lamp lights, you have a "draw." Start pulling fuses, make sure everything is off, dome, courtesy, trunk, etc, lights, any other accessories. Disconnect the alternator stud, and tape off. Pull the horn relay. "Wiggle" "stuff."