Melted wire help!

[tucknroll]

Hey guys, my 69 charger has done fine for years until the other day. Alternator gauge went into the negative and I smelled smoke. Noticed the bulkhead connector was melted where the alt wire goes in. Middle section, lower side second to the left. Pulled the bulkhead and the black wire goin to the alt gauge is melted and broken. Question is wonder what would cause it. It was a 90 amp and worked fine for years. Tested bad at the parts house. Any help on why it happened?! Thanks

[b5blue]

Run away charging. Bad regulator? No fuse-able link? I've protected my ALT. output with a 60AMP fuse but my 70 is different than yours. (Plus using a 120AMP Denso.)
Good time to switch: https://www.qualitypowerauto.com/pages/ChryslerMegaAmp.php

[tucknroll]

I got new ballast , regulator and alt goin in. Ballast resister was broken. Hopefully that's all that caused it. Anybody think that could've been it?

[70 sublime]

If your voltage was too high that might cook the ballast resistor
Either the resistor is working or not
I do not think if the resistor stopped working it would have anything to due with melting wires 

[Nacho-RT74]

You fall into the weakest point of the charging system... bulkhead. Is not an alt fault per se but the total load requested by the car and the packard terminals hability to hold those loads. Get into the stickied thread on board.

[birdsandbees]

^^^^^ what he said! And give some thought to the fact your car came off the assembly line with a 37 amp alternator!

[Nacho-RT74]

Still with 37 amps alt the bulkhead would end being fried. Maybe even faster, because that low alt capacity will make to request constantly batt assitency, so the alt will be sourcing for more time not just the car needs but also the batt charge status ass soon you rev up the engine. This stress out even more the bulkhead.

The alt upgrade is just an step forward BUT if the bulkhead was already although just slightly damaged by the previous years, the degradation process already began and was late from being saved with just the alt upgrade.

[John_Kunkel]

I'd be looking for a short at the ammeter itself.

[tucknroll]

You mean the actual gauge in the dash could be the problem too?

[metallicareload99]

I'd be looking for a short at the ammeter itself.

Last time I had a big short, it was the ammeter studs shorting to the gauge's backing plate. The insulation seems to be made of cardboard 

[tucknroll]

Seems odd to me that it melted on the cabin side of the meeting at the bulkhead. Makes me wonder more and more about that gauge

[Nacho-RT74]

Don't get worried about the gauge. Yes is time to check it (~50 years of abuse on it ) but with a 90 amps alt is even safer than with the stock alt. Time to check the studs with the internal shunt conditions and the chassis mount insulators.

Insulators it can be even homemade (masonite or even any old PCB laying around, removing the metal layer of course ) but are available as repro here

https://premiumdashdecals.com/shop/dodge/dart/dart-demon/all-car-lines-ammeter-insulator/

TRUST ME.

I can post here half of dozens of threads talking about the ammeter goods and how to keep it safe. Unfortunately there are even more threads about the fearness about the ammeter. Unkownledgement is the bigger deal here.

[Nacho-RT74]

BTW, a short on ammeter itself will blow instantly the fuse link. It won't be a slow short, but an instant and HUGE short getting sparks everywhere. So no, this is not a short issue, but resistance on wiring due the bad conditions on connections.

Why bigger melt inside than outside? Because the main splice is inside the cabin sucking the required load between the conection and the splice. The bulkhead terminal conditions or performance is limiting the requested load, so it becomes on a resistor, just like an old electrical kitchen.



A loosing stud into the amm will become on a high resistance area too. But that's an easy fix if required.

[tucknroll]

Thanks everyone. I've always had trouble with loose connections at the bulkhead. Thinking there's gotta be an upgrade to fix it after 50 years

[tucknroll]

Got my bulkhead out into the floorboard. Got a news one and female connectors coming. Hopefully it was just a loose connection

[Nacho-RT74]

new bulkheads are available allmost everywhere. Remove all terminals. Clean them with degreaser and brush (teethbrush), then sink them on a vinegar and and salt solution for 3 or 4 hours ( maybe over night depending on conditions ) then clean with baking soda solution and reinstal those on a new bulkhead conection.

get AT LEAST the alt wiring bypassed out of the bulkhead without terminals ( solding wires ). Batt wire is good too but COULD be not mandatory.

if you want to go even deeper int the upgrade, don't use anymore the existant 12 gauge black wires and run a new 10 gauge wire straight between alt and amm. Existant 12 gauge wire on amm must remain in place, but isolate the end running to the bulkhead.

Check the wires around the black melted wire for isolation damages.

[tucknroll]

Thanks! I've heard of packing them with grease. Like bearing grease?

[Just 6T9 CHGR]

Thanks! I've heard of packing them with grease. Like bearing grease?

Dielectric grease

[tucknroll]

This site never fails me

[tucknroll]

Hey last question hopefully. How do I get the old female ends out of the old connector without tearing it to pieces? I'd like to put them in the new one 1 at a time

[70 sublime]

The female conector should have a little prong that sticks out to keep it locked into the plastic socket
If you take something very thin and slide it down the outside of the flat side of the metal conector it should pop the prong in and push the conector out of the plastic holder at the same time
You do this from the open end not the wire end

It might take a couple tries to find something thin enough to work and fit in the space

[Nacho-RT74]

Kinda long video to explain this ( could be explained in 10-20 seconds) but...

https://youtu.be/_3GoK3xE1gs

BTW if you make one at a time it means you won't get them sink on any clenaning solution?

Don't be affraid about get them out all together. Diagrams are everywhere and cavities are labeled with letters/numbers

You have to deal with just 20-24 wires ( depending on options ) not 100-200 wires LOL. Is really easy.

You can if you want label every wire with masking tape and a sharpie from the cavity is coming out if you want to make it even easier.

[tucknroll]

My new alternator is 75 amps. Should I put an inline fuse in the wire somewhere and what size?

[b5blue]

From output, try a 60amp. 

[Nacho-RT74]

No need for fuse link from alt output. Just batt side is fairly enough. If some heavy short floats on( out of the fuse box protection areas ), the only source able to keep feeding the short is the batt. As soon the fuse link blows on batt the engine will stall. Alt is not able to hold a short alive.