Preventing A Fury Fire

Joseph James

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I have had a voltage drop for a while now. Wipers slow to a crawl at idle, etc. This week, I left parking lights on and totally discharged the battery. Since then the ammeter indicates nearly full right when above idle. It should settle down after driving.

I checked the alternator output with an ammeter I have that features a DC clamp meter (thank you Fluke). I then checked voltage at alternator (15 volts) and at battery (13 volts). I have a significant voltage drop. Ergo, I have high resistance in the circuit and is a classic fire waiting to happen.

I examined the wiring and the battery conductor at the bulkhead connector has been spliced previously. The splice hasn’t held up. So, today’s project is to reroute new 10 gauge wiring through an existing firewall grommet. I will be using a mechanical butt splice as I don’t trust a standard butt splice to carry the load of the entire electrical system. I am using some 10 gauge THHN I have several spools of. It is rated 90 degrees centigrade and is oil/gasoline resistant.

I will not be bypassing the ammeter. I like it. I recently had the instrument panel out and had to remove those connections. They were cleaned up and tightened really well.

B22C02C3-CDB1-491F-9BEA-4BA7F1F21895.jpeg
 
I am not a fan of those type of connectors in automotive. Vibration and what not may allow the screws to back out over time. Nor am I a fan of THHN wiring which I believe is recommended to run through conduit. The insulation is usually more brittle as well.
If you do use that connector be sure to insulate it well. Just wrapping in electrical tape will not cut it. A couple layers of electrical shrink tubing may help keep it from wearing through on something and grounding.
My opinion.
 
I am not a fan of those type of connectors in automotive. Vibration and what not may allow the screws to back out over time. Nor am I a fan of THHN wiring which I believe is recommended to run through conduit. The insulation is usually more brittle as well.
If you do use that connector be sure to insulate it well. Just wrapping in electrical tape will not cut it. A couple layers of electrical shrink tubing may help keep it from wearing through on something and grounding.
My opinion.

THHN is pretty sturdy. I have no qualms about using it. Insulation becomes brittle due to heat.

I have used mechanical butt splices on factory equipment, service drops, etc. I trust way more than a crimp butt splice.

Yes, I have heat shrink.

Photo of existing splice.

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Wire on alternator side had a broken connector. Wire on battery side shows signs of overheating.

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Done. Idling with ammeter in center now instead of below. Wipers aren’t slow in idle. Only headlights really put it down.

No voltage drop between alternator and battery, which is what is important to me.

The original style male terminals are on eBay. I may buy them and put everything back as built. I prefer original.
 
Your melted/burnt butt splices are the reason I don't like using them. I prefer to solder wires and heat shrink. I have heard people complain about soldering too though.
 
Your melted/burnt butt splices are the reason I don't like using them. I prefer to solder wires and heat shrink. I have heard people complain about soldering too though.

I have solder but normally only use it on electronics. It is a habit from working in the electrical trade where we can use solder but cannot solely use it without a mechanical connection. So, I am not against it, just not in the habit.

I really am considering buying new male connectors on eBay. They are the Mopar style. If I install them, they should last my lifetime. After all, the original ones made it 50 years :)
 
The issue with soldering is the solder tends to get brittle with the vibration.
I have found some butt joint connectors that have a band of solder in them and a heat shrink wrap to support them. They are pretty slick. Push the wires together inside the heat shrink connector and hit it with a heat gun. The solder ring melts and Solders the wire and the heat shrink contains it all to make a nice air tight connection. Not sure if they go up to 10 gauge.
image.jpg
 
I really am considering buying new male connectors on eBay. They are the Mopar style. If I install them, they should last my lifetime. After all, the original ones made it 50 years :)
Terminals for the bulkhead connector?
 
I'm not going to criticize using connectors. I'm just going to say that I have been working on my own cars (and a few friends cars) since 1981. I have always twisted two wire ends together, end to end, and then soldered. Lately, I've been using heat shrink, but back in the day I used to just double wrap with tape, first one direction, then the other. In all of that time, I have never had to go back and fix the same solder connection.


Your melted/burnt butt splices are the reason I don't like using them. I prefer to solder wires and heat shrink. I have heard people complain about soldering too though.
 
I'm not going to criticize using connectors. I'm just going to say that I have been working on my own cars (and a few friends cars) since 1981. I have always twisted two wire ends together, end to end, and then soldered. Lately, I've been using heat shrink, but back in the day I used to just double wrap with tape, first one direction, then the other. In all of that time, I have never had to go back and fix the same solder connection.

A valid way to do it. Usually there is more than one way. I am probably doing overkill and it’s just due to things I have seen fail over the years in non automotive applications.
 
Yes. I also see some of the bulkhead plugs (not sure official name) that the connectors go in. I wondered if they were available as I have never seen the male ones before. They have an odd design. I’m guessing they are made that way to lock them in the plastic connector.

Mopar Wiring Connectors Bulkhead A B C E Body Cuda Challenger Charger RoadRunner | eBay

8 bucks plus the ship? I take it OEM means Made In The USA?

I take it if these are still around in the USA via a manufacturer here, if you live close to a metropolitan area you should be able to source these from a good electrical connector supplier locally, like a box of 50 or a 100 for that price IMHO.

MOPAR.BULKHEAD.CONNECTORS.(SPADE).jpg


My question is are the male spades of the correct material as I seem to remember that they were of a brass composition (same as the females).
Now we can start a argument of dissimilar metals in a electrical connection reacting!
 
8 bucks plus the ship? I take it OEM means Made In The USA?

I take it if these are still around in the USA via a manufacturer here, if you live close to a metropolitan area you should be able to source these from a good electrical connector supplier locally, like a box of 50 or a 100 for that price IMHO.

View attachment 306768

My question is are the male spades of the correct material as I seem to remember that they were of a brass composition (same as the females).
Now we can start a argument of dissimilar metals in a electrical connection reacting!

I will look around. The eBay seller gets them from somewhere.

The old ones do look brassy.

No argument from me on mixing metals and electricity. :)
 
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Use these butt splices with a micro butane torch + solder. Use heat shrink tubing to seal it up. Not the easiest to work with under the dash but the most reliable. Your stock alternator puts out 60 amps, this is no place to use inferior quality products.

The stock terminals can be found at delcity.net. They also sell many of the plastic housings too. Although not every variant. Decent prices too.

The dissimilar metals thing. I believe the silver terminals are zinc plated. Brass is made of zinc and copper. Not an issue.
 
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