Factory ammeter

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Guys, maybe this is too simplified. I like the idea of connecting the alt wire to the black ammeter wire. What about reducing the number of wires sold
Fuse Block.jpg
ered together and using the vacant fuse post? See the picture...
 
This is a drag car and making repairs to the wiring harness w/o replacing it. Aside from the fuse block melt. I have replacement fuse terminals and 90% of the harness is good. Getting the car up and running with a 440. I moved the melted terminals to the 4th terminal since I deleted the rear window defrost and headlight buzzer wiring.
 
The wires at those junctions are not soldered together. They are welded.

A schematic of just the main circuits looks something like this.
You can confirm/correct the details using your FSM and what you find on the car.
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The junction where the alternator output meets the battery feed can be thought of as the power distribution point.
From this junction power, regardless of whether the power is coming from the battery or from the alternator (engine running) its going to go to either the key switch, the headlight B1, or the hot buss of the fuse box.
Additionally, if the battery needs charging and the alternator can provide it power, current will flow into the battery line.
 
Mattax, thank you. I agree with your assessment. My choice of words was not correct on the soldered reference. Thank you for that. It seems to me that the welded section can be made cleaner by moving 1/3 of the wires to the vacant terminal. Here is the fuse panel as I am reworking it. I see now that someone makes a replacement box. Thx
Panel.2.jpg
 
carguy47 said:
This is a drag car and making repairs to the wiring harness w/o replacing it. Aside from the fuse block melt. I have replacement fuse terminals and 90% of the harness is good. Getting the car up and running with a 440. I moved the melted terminals to the 4th terminal since I deleted the rear window defrost and headlight buzzer wiring.
Click to expand...

Then the factory harness should be plenty adaquate assuming this is not an EFI conversion.
So the only things the alternator really needs to do is run the ignition and recharge the battery after starting.

Here's what the flow would look like if the car is running and foot is on the brakes.
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carguy47 said:
Mattax, thank you. I agree with your assessment. My choice of words was not correct on the soldered reference. Thank you for that. It seems to me that the welded section can be made cleaner by moving 1/3 of the wires to the vacant terminal. Here is the fuse panel as I am reworking it. I see now that someone makes a replacement box. ThxView attachment 1715695009
Click to expand...
Unless its been damaged, the welded junction is going to make a much better connection than the push connectors.
If the welded junction has been damaged, then a good repair such as an in-line soldered crimp splice would be my first choice.

Do you have any idea what caused all the damage?
The hot buss is usually just brake lights, parking lights, dome and hazzard.
Everything else is usually on the switched buss.
The middle fuse holder that you repurposed was the optional/accessory fuse. It could be for A/c or the rear defroster or a tach.
 
Yes, the prior owner at some point in the past bastardized the wiring and cut into it in multiple areas. I found several areas were the wiring was exposed and touching other wires. Since the car was already cutup and set up for racing, I figured I would make the repairs and use the existing harness. Eliminate the heater, rear defrost, cigar lighter, wipers, etc.. I have tested the front circuits (headlights, markers, horn) and the rear harness (fuel sender, tail lights, markers, license) and all work great. Since I pulled the dash harness, I figured I would make repairs, and most are start to finish with better wiring.
 
Since L1 and H1 are so close to the fuse box, this would shorten the wire length and clean the connection up.
 
Chrysler had a couple ways of reducing the maximum current that might have to go through the bulkhead connector. They did this on cars with leece-neville and Chrysler 60/65 amp alternators. And/or also on later A-bodies with rear window defroster grids.
The basic concept is the same on all of them.
a. Run a heavier wire from the alternator through a grommet in the firewall.
b. Split the maximum load. Usually this was done by keeping the standard wiring path through the bulkhead while having a second path for charging the battery.

A simple version of that is a parallel alternator output wire going to the ammeter.
The orange arrows represent current flow if the battery was getting recharged at the same time the lights and wipers were on.
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This arrangement only requires one fusible link.

Because my b'cuda has an MSD, you'll see in the finished photo the single terminal junction is also used for the main power to the MSD 6T.
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This way the ammeter only shows power into or out of the battery.
It also connects the MSD power closer to the power source.

I got the idea from this optional '73 B-body scheme.
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If you're replacing the engine side harness then this is another option.
In my case I decided I didn't want to unwrap the existing harness. That was the main reason I added a second parallel wire from the alternator.
I dont see a need for you to be running 6 ga wires between battery and the terminal block. But notice they protected the 6 ga with a 10 ga fusible link. Then they protected the 10 and 12 gage wires inside the car with a 16 ga fusible link.

Plenty now for you to think about!

One more suggestion for reducing the maximum current through the bulkhead connector. If you'll be driving at night, add a headlight relay system. Power it from the alternator. These cars came with 40 W/50W headlights (6012 bulbs), the headlight routing is long, and the wiring is small (16 gage to the hi/lo 18 ga to the lamps). Dan Stern will sell you a kit. Crackedback sells ready made harnesses. I made my own, but both of those guys provide quality stuff.
 
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carguy47 said:
Here are the terminals I found on eBay...
View attachment 1715695030
Click to expand...
Those look great! If you can share the listin that would be grreat. Last month someone was asking me about where to get those. I had bought some used ones for the tab side and got the crimp terminal from Bill Evans. The latter was an AMP product.
 
carguy47 said:
Since L1 and H1 are so close to the fuse box, this would shorten the wire length and clean the connection up.
Click to expand...
I think you see now its longer path to go the buss on the box and through those push terminals. Each push terminal has resistance at the wire connection to the terminal, and to the mating terminal.
 
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I was looking for those! Im finishing up our 67 rally dash harness. I was replacing a double pink at the fuse block(amongst others) and pried open and reused an original. Got a link? I have an extra fuseblock in good shape if you are looking for one?
carguy47 said:
Here are the terminals I found on eBay...
View attachment 1715695030
Click to expand...
 
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If you have a numbers matching car, the fuse panel will not meet your criteria since it is a different number.
 
4spdragtop said:
View attachment 1715695143 View attachment 1715695144 View attachment 1715695144 View attachment 1715695145 I was looking for those! Im finishing up our 67 rally dash harness. I was replacing a double pink at the fuse block(amongst others) and pried open and reused an original. Got a link? I have an extra fuseblock in good shape if you are looking for one?
Click to expand...

I used these connectors. I think there should be a wider terminal for the areas where 2-wires connect, however I was able to get them to work. I soldered the connections and then used heat shrink.
 
carguy47 said:
I used these connectors. I think there should be a wider terminal for the areas where 2-wires connect, however I was able to get them to work. I soldered the connections and then used heat shrink.
Click to expand...
At one time there were double wire connectors for Packard 56 and 58 series terminals.
Some are still available.
See the second one from left in the photo - and the ones in the table with a (2) next to the wire gage.
Sources for Chrysler type wire terminals
 
I think you're correct. The surface area of the contact is important for good electrical flow. Also the terminal is thin relative to a 10 or even a 12 gage wire.
Its where I often see heating when subject to long periods of high current.
Notice the heating metled away the moisture seal around the crimp. I beleive this terminal saw 25 to 40 amps for 20 to 30 minutes.
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Above is the R6 wire. Below is the Fusible link. Again the heat build up is at the crimp. The damage is not quite as bad, probably because it didn't see as much current, and possibly because the crimp was better made or the terminal a little better quality.
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Of note is these same terminals on this car's original '67 harness don't show this damage. This happened under my watch, not the first 150 or 250,000 miles. (Mostly because I left the parking lights on in a remote location)

A couple of more from this car. These are wires from the key switch connector.
My guess is the accessory feed saw additional current loads from the aftermarket A/C unit that was added to the car in the late 60s or early 70s.
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One more. Headlight power into the switch. Looks like the highest resistance here was the terminal contact.
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And of course there is an example a couple pages ago in this thread showing the damage to terminals that saw over 40 amps through them for over 20 minutes.
It's actually impressive how well they did.
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