Ammeter pegged to plus on my 74 318 duster?

[2XDusterGirl]

This is my second duster a 1974 318. Always worked on it myself redone suspension, steering parts, interior, carb and manifold, minor body work, and guages.
Always had some electrical issues (who doesn't with these) but I fired her up this morning and my ammeter was pegged to plus took a look over everything and nothing was standing out to be wrong. Alternator started squeeling and shut it off right away.
About 4 months ago had a small dash fire which seemed similar to this issue (hence the new guages) So, problem seemed solved.

Must be a short somewhere ANY clue what I should be looking for when trying to solve this issue?

 

[Abodybomber]

Might want to check or try a new voltage regulator.(Just a guess)

 

[67Dart273]

First, is it possible something is taking the battery down? Glove light/ radio on? Take a voltmeter and see if it's regulating or over charging (voltage) Depending on if the battery is low or high, "normal" running voltage should be 13.5-14.5. Much higher than that shows it's overcharging


Second thing to do is unhook the regulator to see if there is some problem in the under-hood harness or in the alternator. If that does not stop it charging, unhook the field (push on) connectors at the alternator ONE and then the OTHER, and see if one/ other/ either stops it charging.

If unhooking the regulator stops it, check the ground on the regulator, might be loose/ rusty.

If it's grounded, and pulling the regulator plug stops charging, probably just a failed regulator.

 

[The Sasquach]

There is a "main" power wire running to the fuse box that may have been burned during your dash fire that is intermittently shorting to the dash , firewall , or somewhere else. I had this exact problem with a '69 Satellite. mine shower it's self by shorting out several voltage regulators ( the older point type regulators). Took me forever to find it due to it running along the lower lip of the dash to the glove box fuse panel. I would be looking at that wire first. David

 

[RedFish]

Since the altenator startered squeeling, it may be the problem. Any part store should be able to test it for you.

 

[jos51700]

There is a "main" power wire running to the fuse box that may have been burned during your dash fire

That main power wire is probably what caused the dash fire, and it sounds like it hasn't been dealt with. Right now, it's probably dumping max alternator output straight to ground, hence the maxed gauge.

Disconnect the battery so the car doesn't burn down while you're asleep, and FIX THIS. The main power feed passes through the bulkhead connector (firewall) and are NOTORIOUS for getting corrosion in that connector. Corrosion=resistance=heat

Once the wiring is fixed (No electrical tape...actually fixed), run a heavy-gauge wire with appropriately sized fusible link from alternator output stud to battery. This makes your ammeter worthless, but you can't read an ammeter through the smoke and flames anyway.

 

[Bulldozer]

That main power wire is probably what caused the dash fire, and it sounds like it hasn't been dealt with. Right now, it's probably dumping max alternator output straight to ground, hence the maxed gauge.

Disconnect the battery so the car doesn't burn down while you're asleep, and FIX THIS. The main power feed passes through the bulkhead connector (firewall) and are NOTORIOUS for getting corrosion in that connector. Corrosion=resistance=heat

Once the wiring is fixed (No electrical tape...actually fixed), run a heavy-gauge wire with appropriately sized fusible link from alternator output stud to battery. This makes your ammeter worthless, but you can't read an ammeter through the smoke and flames anyway.

well put lol XS2

 

[2XDusterGirl]

Who in their right mind would put a chinese made regulator on an american car? Not me thats forsure! Problem solved!
Just ordered a new wiring harness and will be doing a fulll rewire here in about a month.
Thanks everybody for the help