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Discussion Starter #1
Sup Guys!?

Any Ideas on what would cause the alternator cable to burn in half?
I have noticed in the last few days that all of my electrical stuff has been slow, windows, blinkers, wipers etc, then this morning I noticed the guage showed the charge level at 8 volts.
I swapped in a new alternator , gauge showed the same. I then noticed the charge cable from the alternator was burnt up.
This truck is stock with no aftermarket stuff such as an e fan ,winch etc.
The only things done in the last month are new fuel pump and LED bulb replacements for dome lights.
What could cause this cable to burn up?
 

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Sup Guys!?

Any Ideas on what would cause the alternator cable to burn in half?
I have noticed in the last few days that all of my electrical stuff has been slow, windows, blinkers, wipers etc, then this morning I noticed the guage showed the charge level at 8 volts.
I swapped in a new alternator , gauge showed the same. I then noticed the charge cable from the alternator was burnt up.
This truck is stock with no aftermarket stuff such as an e fan ,winch etc.
The only things done in the last month are new fuel pump and LED bulb replacements for dome lights.
What could cause this cable to burn up?
A bad alternator. The Taurus I flipped Had a bad alternator and it had started to melt the insulation on the end of the charge cable. The fusible link is supposed to open to prevent things like this but Even a short doesn't always draw enough current for that to happen. It's also possible that an alternator went bad at some point in the truck's life and caused that damage but the PO just didn't fix it. The 90 I had had a melted alternator plug from when the last one burnt up under prior ownership.
 

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Discussion Starter #3
If you look at the second picture you can see that there was a factory butt splice where the small yellow wire is....its the splice that actually burnt up

Yes, could have been the alternator which had 256,000 miles on it
 

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I got my $$$ on 20 years worth of corrosion.
 

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Discussion Starter #5
I got my $$$ on 20 years worth of corrosion.

I'm wont take that bet cuz I'm thinkin u are right. I think the fusible link to cable splice connector corroded and failed.
As you can see in the pic the damage did not occur at the fusible link, it failed at the splice
 

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Discussion Starter #6
The subcontractors that Ford uses for wiring harnesses don't use crimped butt splices. They resistance-weld the copper strands together, then tape, mold rubber, or waterproof-heat-shrink over that before building it into the harness. That was a repair. :rolleyes:
http://www.supermotors.net/registry/media/830776
Gunna have to disagree on this one. It wasn't a repair it was a crimped butt splice.
Believe me...not all subcontractors follow the rules or provided drawings and don't ask me how I know
 

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Discussion Starter #7
Steve, Im not arguing with you by any means...but you have no idea what goes on inside the shop of a subcontractor. Unless you've ripped open every wiring harness on every Ford Bronco ever made..then well....ive seen stuff hacked together to meet deadlines and quotas.

I should have looked closer before I posted. Once I saw the cable had failed at the splice I knew what the problem was or what caused it to burn up.
I guess this post can be deleted
 

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yo J,
Any issues with this?
Connector, IAR Burn-Up, Ford; "...Due to a design flaw from the factory these units are prone to burn up. When replacing these units it is very easy to spread the wiring harness connectors. When this occurs, an electrical arcing takes place and will burn out the unit and harness. Due to excessive heat buildup at the output terminals the original plug is usually brittle and cracked, this is not something distinguishable by the naked eye. Chances are it is damaged and not useable. You will notice that OCA IAR units come with a brand new wire plug and installed with dielectric grease..."
Source: by mrreman.com via http://web.archive.org/web/20051119104754/http://www.mrreman.com/downloadsgateway/FORD/MRTSB-FORD-001.htm

and

Alternator Fires. The Vehicle Fire Reporter. Lee S. Cole & Associates. Volume 1, Spring 1997.


Abstract: While most vehicle fires are the result of flammable liquids found in vehicles, there are also other causes. A malfunction in the alternator, the device that produces electric current, is another vehicle fire cause. There has been a recent investigation of alternators manufactured by Ford. This article provides facts and information from the Ford investigation.

In one instance, the driver smelled smoke and discovered a fire underneath the hood of his Ford Aerostar. After the Fire Company extinguished the fire, investigators determined that the wiring at the plug connector melted and caused high resistance overload. According to the National Highway Traffic Safety Administration (NHTSA) there are 75 fires allegedly caused by the Ford Alternator. Ford uses a plug connector and not the conventional attachment. Investigators think that this plug connector develops high resistance over time and becomes even more dangerous when it is removed and reconnected. Currently Ford and the NHTSA are conducting further investigations into Ford alternators.

Another cause of alternator fires involves repairs. When an alternator is replaced, the connector should be examined. If the connector is not in good connection, it should be replaced as well. A damaged connector can cause wire melting and subsequently cause a fire. The replacement alternator must also be the correct one for the vehicle. A 75 amp alternator cannot replace a 65 amp alternator. The additional output can cause melting and a fire. The article lists other safety precautions to take regarding alternator repairs.
http://web.archive.org/web/20101124063910/http://interfire.org/res_file/fseab_tv.asp
 

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Discussion Starter #9
Good and helpful stuff Miesk! Thanks!
 

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With all due respect the article miesk posted pertains to the ford vehicles nearing my Bronco's era. Scatts is the newer design or last generation.
 

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Good and helpful stuff Miesk! Thanks!
Yo J,


With all due respect the article miesk posted pertains to the ford vehicles nearing my Bronco's era. Scatts is the newer design or last generation.
Yo H,
Correct! I was just showing J that info just in case a PO or shop replaced original w/a yard queen harness, alt, etc.


...This thread is about a splice inside the harness; not a connector...
yo Steve,
I was just showing J that info just in case a PO or shop replaced original w/a yard queen harness, alt, etc.
 

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yo J,
I forgot to ask; re you;
"...swapped in a new alternator , gauge showed the same. I then noticed the charge cable from the alternator was burnt up..."

Was it yard or a new Alternator?


One more for posterity;
Loose or Weak Contact at Generator Harness Connector TSB 96-21-4 for 86-93 Bronco & F Series, etc.
Source: by Ford via Steve83 (Steve, That dirty old truck) at http://www.supermotors.net/registry/media/723349
TSB 96-21-04 Generator Harness Connector

Publication Date: OCTOBER 7, 1996

FORD: 1985-90 ESCORT, TEMPO
1986 TAURUS
1986-90 CROWN VICTORIA
1987-92 THUNDERBIRD
1987-93 MUSTANG
LINCOLN-MERCURY: 1985-87 LYNX
1985-90 TOPAZ
1986 SABLE
1986-90 GRAND MARQUIS, TOWN CAR
1987-92 COUGAR
LIGHT TRUCK: 1985-90 BRONCO II
1985-91 AEROSTAR
1986-91 ECONOLINE
1986-92 RANGER
1986-93 BRONCO
1986-94 F-150-350 SERIES

ISSUE: When a generator fails, there are a few failure modes that may cause heat to be produced at the wiring harness-to-generator connector. This excess heat may damage the female terminals on the wiring harness, resulting in increased resistance. The increased resistance produces more heat. When the generator is replaced, the resistance produced by a damaged connector may damage the new generator and could result in a repeat repair, including installation of another generator. High resistance (caused by a damaged connector) will not go away until the damaged connector is replaced.

ACTION: Visually inspect the harness-to-generator connector for damage (heat, corrosion, distortion and cracking) before installing a new generator. Install the Generator Wiring Harness Connector Kit (E5AZ-14305-AA) if the harness-to-generator connector is damaged.

The Generator Wiring Harness Connector Kit (E5AZ-14305-AA) contains the following:

One (1) Red Wire Butt Connector
Two (2) Yellow Wire Butt Connectors
One (1) Wire Connector Assembly
One (1) Instruction Sheet (I.S. 6849)

PART NUMBER PART NAME
E5AZ-14305-AA Generator Wiring Harness Connector Kit

OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 95-25-04
WARRANTY STATUS: INFORMATION ONLY
 

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I unfortunately am still running a newly replaced 2g. Sorry I burnt brushes in the old one up and swapping a 3g in the parking lot at autozone was not a timely option given the long day of beating the drivetrain that day.
 

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Discussion Starter #14
I just remembered today that the burnt cable I have is actually a 3g cable that came of I believe a mid 90's T-bird.
I now remember doing the up-grade to 125 amp alt and cable.
Regardless, this was the factory cable that failed.

And Miesk...the cable originally failed with the yard alternator.
I have not had the alternator tested

Steve, is it possible that the 125 amp 3g cables also had the splice I described? The one that failed?

Anyway, I am back to the stock 2g 95 amp alternator
 

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just had a similar issue with my 91. swapped out the alternator after it took a dump and noticed the wires were a little crispy. I have delt with it on motorcycles coming out of the Regulator / Rectifier and looked at all the connections and sure enough down the harness was a hack job with a few butt connectors where it looks like a previous owner spliced in a new plug and even left a good bit of exsposed wire. It was pretty terrible and I was getting similar gauge readings at the dash. Cleaned up the wires and installed new connectors till I can order a new plug or find on in the scrap yard that is worthy of use. Gauge readings are fully back to normal and looks like its going to be okay for a week or so.:rockon
 
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