Toasted Circuit 71 Charger

[Archie340]

Probably happened many years ago but the main wires from the battery (red) and alternator (blk) going thru the bulkhead to the ammeter are fried under the dash. I understand this was not uncommon back in the day. The red wire overheated and fused several wires together including my horn which was getting constant power from the battery. The black wire was hot enough to burn off insulation and is partly bare. Car runs but I'm afraid it's only a matter of time before something catastophic happens.

My idea is to drill holes in the connector and run both wires (Red/Blk) thru the bulkhead without the male/female connectors which I understand are a problem area and solder in a second fusible link (Alt) past the bulkhead to protect the circuits in the passenger compartment. I read about bypassing the ammeter but mine still functions so I want to keep it. What do you think?

 

[Nacho-RT74]

the problem on the original system is the poor capacity of the alternator iddiling, not able to source the basic car loads ( which keeps mostly constant while working ) and making the batt to provide the power alt is not able to give. This made when you rev up the engine, the alt to work enough and recharge what the the batt lost while iddiling, get higher loads than the terminals are able to support. This is not really a short, but unnecesary overloads, more than the car actually sucks, but the battery sucks back to get its chemical balance

you can rebuilt your system like was stock, but AFTER THAT the real and best solution is an alt upgrade, able to give around 50-60 amps iddling. Hard to find from an old stock Mopar alt, but they exist from lates ( earliers 80s alternators or newer aftermarket one on older cases, if you care the stock look ).


This will save your wiring and even the ammeter health ( believe or not ). An extra wire from alt stud to ammeter studd will help you even more.

thats MY opinion... I have a nice topic wrotte around about that, but running to job right now. I bet somebody else will post the link

 

[Archie340]

Thanks Nacho, just looking for opinions. I'm going to have to check the output of my alternator. What I have done so far is to reroute the wires (now 10 ga) from the alternator and battery thru a grommet in the firewall and not the bulkhead. The read batt wire goes directly to the ammeter and the black connects to the factory splice to provide power to the fuse box etc. I am planning to put a fusible link at the alternator stud to protect the wiring going to the splice but adding a wire from the alternator directly to the ammeter sounds interesting.

 

[72RoadrunnerGTX]

The bulkhead connector bypass on the charging circuit, upsizing the wires, is a highly recommended upgrade for any old Mopar. Adding a fusible link at the alternator would not be unnecessary as the Battery is the source of power with ability to burn those unprotected wires. Your diagram indicates locating a fusible link in the passenger compartment, not a good idea. When they blow they generate a ton of smoke.

http://www.forbbodiesonly.com/moparforum/showthread.php?82326-How-To-Upgrading-Wiring-and-Alternator

 

[mopar 3 B]

Go to 8 ga and solider all connections.

 

[Archie340]

Thanks, lots of great info. Assessing the damage I found the red (batt) wire overheated (melted insulation) with damage to the bulkhead connector even though it was protected with a fusible link?? The black wire (alt) suffered a complete melt down to bare wire from the bulk head to the factory splice. I still don't really understand what would cause this, lack of output from the alternator at idle or resistance from bad connections. Sorry I'm kind of a nube at this but I'm catching on... I know the page numbers of the wiring schematics in the service manual by heart and I watched a couple episodes of the old chrysler master tech series Lol!!

 

[dvw]

Have been running my Challenger for 10 years. The wires (8g) are drilled through holes in the firewall plug. I run an 100amp alternator, no issues.
Doug

 

[uwss]

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