Battery becoming very hot

[Mattax]

@Eddie348 Lets see where the battery feed connects. Then do the same for alternator.
Battery Feed is what I'm calling the smaller wire attached to the Battery positive terminal.
In this photo, it looks like it attached to the stud on the starter relay.
Step 1. Can you confirm there is just one other wire attached to the stud?

Step 2. Follow this Heavy red wire and see what it attaches to next.
It looks like its this one with the arrow pointed to it.
If so, what does it attach to next?

If you find it attaches to a special wire marked fusible link, that's factory. That in turn should go into the big connector on the firewall.
But you may find something different. Let us know.

 

[Mattax]

Alternator feed is what I'm calling heavy black wire that carries the alternator output to the main junction.
Please confirm the heavy black wire is the only one attached to the output stud.

See if you can find the other end of this black wire.
It should be the only heavy black wire going into the bulkhead connector on the firewall; but something could have been altered.

Black arrow show where the alternator output wire originally connected on the bulkhead.
Blue and red arrow shows where the battery feed wire originally connected on the bulkhead. (The fusible link will probably be blue)

It wouldn't surprise me if you find additional wire spliced into the battery feed, but lets see.

 

[Mattax]

@Eddie348 A test that should help narrow down where to look.
Turn on the headlights with the key off. See which way the ammeter moves, if at all. Also see if the cigar lighter volt gage registers anything.

Then turn key to accessory and turn on the heater fan.
Note the ammeter and voltmeter.

You can do this before tracing the wires if you want.

 

[Mattax]

Turn on the headlights with the key off. See which way the ammeter moves, if at all. Also see if the cigar lighter volt gage registers anything.

Then turn key to accessory and turn on the heater fan.
Note the ammeter and voltmeter

Hope you haven't given up on trouble shooting this.
If the ammeter always shows charging with the engine running and never shows flow with engine off there's a good chance someone wired it into the alternator output line. That's my best guess right now.

 

[Eddie348]

Good evening Mattax- will not give up.
Thank you for all the assistance see below
Igniting off
12.30 volts pre turning lights on.
11.60 volts post turning lights on
Acc On
Volt 11.81
Volt 11.66 blower on high

 

[Eddie348]

Good evening Mattax- will not give up.
Thank you for all the assistance see below
Igniting off
12.30 volts pre turning lights on.
11.60 volts post turning lights on
Acc On
Volt 11.81
Volt 11.66 blower on high

 

[Mattax]

That's interesting on a couple of points.
Did you look at the ammeter when you did these tests?
^^This will be the big clue. Which direction the ammeter moved, if at all?

As far as the voltage readings go.
key off shows that the lighter is hot all the time. That's correct.
Both tests show drops with for the load that suggest the battery needs to sit overnight on a slow charge like Tooljunkie mentioned.

 

[Eddie348]

Yes ammeter did no move with ign off or on ACC.

 

[Mattax]

Yes ammeter did no move with ign off or on ACC. View attachment 1715242077 View attachment 1715242078

Thanks. Sorry about the slow responses. It says you replied 16 minutes but it just showed up now. Weird.

My bet is the battery feed and alternator output wires were switched. If so, maybe the person who rewired for the 70 up voltage regulator didn't keep track of the original layout. When he went to put the new alternator and battery feeds back into the bulkhead, he simply swapped the positions.

Let me look at your photos from the inside and see if I can understand what was done there.
If you can check the engine side and/or get a photo, we're looking to see what wires go in at P and J.

 

[Mattax]

If the blue wire in both photos is the same, then the wire 'swap' is on the inside. Please confirm.
Most likely one of those two black wires on the ammeter's 'red' stud goes to the main junction. If so, that's why the ammeter reads wrong.

Check the engine side wires. Those could have been altered as well.
The red one should connect to a fusible link and attach at position J.
The heavy black from the alternator should go into position P.

Then we can discuss fixes.

 

[Mattax]

Here's how I *think* it was modified based on what we've seen so far.

 

[Eddie348]

Mattax- Thank you for all your assistance. Been working alot and just got home and began working on the Dart. Please see below blue wire goes to alternator

Black wire has a fusable link and goes to starter relay

starter relay

It might be like you said the other black wire on the red stud on the ammeter. I do not know where that one goes.
Also do you know what the plug in the picture belongs to? Found it as I was looking at the wires.

 

[Mattax]

Mattax- Thank you for all your assistance. Been working alot and just got home and began working on the Dart.

No prob. Lets see what you got and I understand what you're seeing and telling us.,
The photos don't always convey the color well so it makes it trickier.

blue wire goes to alternator.

If I understand correctly, the alternator output wire (looks black in photo of alternator) connects to the blue wire(you're holding in second photo) going in at position P?
Did you see a splice or is the whole length blue?

Black wire has a fusable link and goes to starter relay

I can't see the black wire, but if this goes in position J, bottom corner of middle connector that makes sense. Since its red at the starter relay same question then. Is there is splice and are any other wires connecter?
View attachment 1715244198

Also do you know what the plug in the picture belongs to? Found it as I was looking at the wires.

Photo is too washed out. Do you have the shop manual? See if the color matches something in that area. Maybe windshield washer pump?

As far as the ammeter connections go, need to verify the blue one in both interior photos is the same wire.

 

[Mattax]

We're getting to a point where there are two ways to figure out wire connections. One will be with a continuity using a multimeter, the other by unwrapping the tape holding the bundles. Are you up to tackling either one?

There's no fuse on these wires (other than the link) so this isn't the sort of diagnosing or repair where we can just try moving wires and see if it works. The battery carries quite a wallop. We want to be sure of what things connect to.

And the second part is whether you're up to doing some wire work?
Its going to involve some crimping, new terminals and maybe some new wire.

 

[krazykuda]

@Eddie348

Call me and see when we can get together and check this out...

 

[Mattax]

Thanks Karl.

I can't see the black wire

I see which one you mean now. It's really fat insulation. Hopefully its a 16 gage wire inside. That's what a fusible link is - an undersized wire with special insulation.
Original probably had a connector attaching it to the red battery feed coming from the starter relay.
Here's what it looked like for '67.

 

[Eddie348]

Mattax- might have to rewire both cables.
Karl and I built the engine, and I know he is awesome on wiring.

Do you think it would be beneficial to change the harness? Thank you

 

[Mattax]

Why?

Mattax- might have to rewire both cables.
Karl and I built the engine, and I know he is awesome on wiring.

Do you think it would be beneficial to change the harness? Thank you

Which one and why?

If the answer to my questions in post #64 are no, have Karl help you.
Even if they are yes, it will go 10 times quicker.
We need positive answers about where each feed connects.

If you want to spend money, use it for buying or renting open barrel crimpers, factory style terminals for various wire sizes and things like that. And a battery charger that can do a slow charge ( 2 amps and under) if you don't have already.