Nearly elect. Fire…

[Steve83]

...it could have been rubbed raw at some spot and caused that pigtail piece to fry.

Yes, where it's crimped to the larger/newer wire looks like where the heat stopped. That means the larger/newer wire was ALSO passing that current, but being larger kept it cooler. And its modern (XLPE/PEX/GXL) insulation melts/burns at a higher temperature than the old (PVC) stuff. So look closely at the new wire continuing from that butt splice, and find where it shorted.

 

[Cortez]

Thanks for the tips, will sleuth some more today.

 

[Rustytruck]

Was the harness not wrapped exposing all wires to chafing? seems small for the main power wire going to the ignition switch.

 

[Cortez]

Was the harness not wrapped exposing all wires to chafing? seems small for the main power wire going to the ignition switch.

It's definitely bigger (red one) gauge than the other wires in the harness, could just be the pic. The wire bunch was all secured together at the point of the crimp connector. Each individually wrapped then the bundle secured. That's why I was thinking a short may have occurred closer to the switch. The red ignition power has no faults in it all the way to the fuse box.

Just snapped a pic here of another clueÂ…the acc. power coming off the stud on the ignition switch looks like it has some melted spot on the red part of the connector and possibly looks to have weakened due to movement or somethingÂ…very few strands holding it together.

The speaker was added 6 months ago. I suspect the speaker activity was just an artifact caused by the short, rather than the root causeÂ…but perhaps running it caused the acc. power line to the fuse box to short out.

Any opinions on this? I have a new switch coming by end of the week so will reassemble and test at that point.

 

[Bronco4x4]

Maybe the speaker work agitated (disturbed) the failed area. It's possible it could have been bumped during the installation. Just a thought.

 

[FordBronc]

This is why I carry a fire extinguisher (even a Wally world one is better than nothing). And ALWASY carry a box end wrench (to fit both battery terminals) in the glove box/center console.

That way if you have to cut power from the battery to the rest of the rig you can do it fairly quick, versus hang grabbing the wire and jerking on it. That wire might be melting also....

Looks like you are on the right path to repair.

 

[Cortez]

This is why I carry a fire extinguisher (even a Wally world one is better than nothing). And ALWASY carry a box end wrench (to fit both battery terminals) in the glove box/center console.

That way if you have to cut power from the battery to the rest of the rig you can do it fairly quick, versus hang grabbing the wire and jerking on it. That wire might be melting also....

Looks like you are on the right path to repair.

Yeah - I usually keep a tool bag but this time realized I didn't have a thing. Would have puking on myself if it went up in Flames.

 

[FordBronc]

I used this one to put out my 77 F250 distributor fire I had a while back. It even comes with a mounting bracket.

https://www.walmart.com/ip/Kidde-Auto-Marine-UL-Listed-Fire-Extinguisher-10-B-C-Rated/737567556

This might fit on a passenger side kick panel and be outa the way, but handy.
https://www.walmart.com/ip/FIRST-ALERT-KITCHEN5-Fire-Extinguisher-5B-C-Dry-Chemical-2-lb/144916710

 

[SteveL]

Did yours char the insulation 2" away from that terminal like his pic?

Pretty much. The problem was nearly identical.

 

[Cortez]

Got it back together today and put power to it, only to let the magic smoke escape again…but this time it revealed the culprit. There was a terminated wire under the hood which had electrical tape over the end which had come off and it shorted out on my inner fender. Once I resolved that, everything was good and back to normal. Me 1 : Universe 0

 

[knack]

Got it back together today and put power to it, only to let the magic smoke escape againÂ…but this time it revealed the culprit. There was a terminated wire under the hood which had electrical tape over the end which had come off and it shorted out on my inner fender. Once I resolved that, everything was good and back to normal. Me 1 : Universe 0

Great job! The smoke-o-graph machine always points to the problem.

 

[gnpenning]

What was the wire for?

Did it smoke on the Engine side for you?

For future reference using a multimeter would have shown a short while you played with wires trying to find it.

Glad you found it.

 

[Cortez]

The wire was just an extra in the harness that wasn't used, and it shorted and smoked on the engine side within about 20 sec. would have been ideal to pull the fuse since it wasn't used. Which raises a question- why didn't the fuse blow?

Gnpenning - Help me with the multimeter process, In order to use the multimeter I thought I have to have the power activated to find the short?

Thx.

 

[gnpenning]

You can use the ohm function and check for continuity between the wire and ground. If it shows continuity you have a short so you follow the wire and move it while keeping a eye on the meter until you find the problem. If you happened to know about the wire in the engine bay you could have started there.

Hope that makes sense.

 

[Jdgephar]

If your "short" has enough resistance, it won't blow the fuse. 1 ohm would give 12 amps, enough to get really hot on a wire that is too small, but not enough to blow a 15 amp fuse.

Sent from my SM-G981U using Tapatalk

 

[Cortez]

Great info guys, thank you.

 

[Rustytruck]

since it is the main power for the ignition switch it should have been protected by the fusible link in the starter solenoid. that should have wrinkled up and separated protecting the whole harness. You need to look into this and see whats up. as it is evident something is amiss. its OK for some things to fail as long as it is protected and failing where it is supposed to fail.