Fire averted!

[BigMex]

I thought of you @KRoyal080 …

A month ago I installed some rear-facing rally lights from F150LEDs, and enjoyed a day-long project of snaking wiring along the frame and hooking everything up just right.

A few times, the lights wouldn’t activate when I flipped Aux #6 and today I decided to investigate. It occurred to me that maybe heat under the hood had something to do with it.

With the engine running and switch #6 flipped on, I saw no lights so I popped open the hood.

The wires from the relay to the upfitter wire splice were WHITE HOT. I could barely hold them without burning my fingers! Had they been bare wires, they would have been glowing red. A minuscule puff of smoke emerged from the area near the splice. I quickly shut off both the switch and the engine, and the wires got hotter. I pulled out the inline fuse to eliminate current and turned around to search for some wire cutters when I heard a pop!

Alrhough there were no flames, billowing white smoke bellowed away from the wire bundle as both the insulation and the sheathing burst open. I was ready to run for the nearest fire extinguisher when I proceeded to clip the wires, cutting their connection to the battery (and hopefully the source for combustible energy).

I suspect there was a short in the harness I was provided. Although I’m an amateur electrician, all of my connections were installed correctly, and this case is beyond my ability to diagnose. I would have thought a fuse would have blown further upstream rather than cause a near fire.

Thank the Lord! I don’t want to imagine had it not occurred to me to pop the hood and troubleshoot things this afternoon…My Bronco was already in the garage and my family is home.

Below you can see the vendor-supplied splice connection and the quarter-inch length of Upfitter #6 cable I sacrificed to disconnect this firetrap.

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[RagnarKon]

Whew close one for sure.

How was it getting power even after the fuse got pulled?? Or was this the wire between the battery and the fuse itself?

 

[Tabman10]

Unfortunately it seems like most of these vendors use cheap china-made harnesses. I had great experiences with 4x4TruckLEDs (sarcasm) when fog light pigtails were pins incorrectly - I inquired and was very rudely told that "their harness aren't wrong"...until I sent a picture. I also noticed that, at least on their 3 light (pocket fog lights) harness the common return wire is the same gauge as all of the other wires - so if each pair of lights is running at close to the max rating for 16AWG, that means that it is exceeded by 200% if someone turns on all 3 lights... I was told that they "haven't had a problem yet". Hopefully nobody really leaves all lights on at once, or they are as good as you at catching it...

 

[BigMex]

Whew close one for sure.

How was it getting power even after the fuse got pulled?? Or was this the wire between the battery and the fuse itself?

I’ll try to figure this one out.

Either the wire reached critical before I pulled the fuse or there was a short elsewhere? Going back from the splice, the cable fed into a relay and another wire (with the fuse) was between the battery and the relay.

 

[JackalOnassis]

Damn that’s wild. I’m super paranoid about this, especially since I woke up two weeks ago at 2am to my neighbor’s house on fire.

 

[Toccoa]

Damn that’s wild. I’m super paranoid about this, especially since I woke up two weeks ago at 2am to my neighbor’s house on fire.

Looks like big trouble in little China. Hope everyone made it out alright.

 

[JackalOnassis]

Looks like big trouble in little China. Hope everyone made it out alright.

Unfortunately that wasn’t the case. I was able to get to the other neighbors house and help get them out before theirs caught. I went to the house in the picture first but by the time I got to the front door, flames were already pouring out. A propane tank blew up and landed in my backyard (about 30 feet away). Opened it up and rolled it out. Fire investigators said they’d never seen one do that before.

 

[604Bronco]

Unfortunately it seems like most of these vendors use cheap china-made harnesses. I had great experiences with 4x4TruckLEDs (sarcasm) when fog light pigtails were pins incorrectly - I inquired and was very rudely told that "their harness aren't wrong"...until I sent a picture. I also noticed that, at least on their 3 light (pocket fog lights) harness the common return wire is the same gauge as all of the other wires - so if each pair of lights is running at close to the max rating for 16AWG, that means that it is exceeded by 200% if someone turns on all 3 lights... I was told that they "haven't had a problem yet". Hopefully nobody really leaves all lights on at once, or they are as good as you at catching it...

Did @4x4TruckLEDs.com replace the harness after a picture was provided?

 

[iSurvive]

I have a lot of experience with aux lighting and wiring - too much if truth be told. My 2012 Ford Raptor had 21 off-road lights and 17 aux switches, and my 2019 Ford Ranger had 13 off-road lights and 6 aux switches. About 5 years ago I was out on the dunes when my Raptor started smoking under the hood. I ran to my chase rack and grabbed my quick-release fire extinguisher and popped the hood, and realized it was my aux wiring. I turned off all the lights and the wires stopped smoking. My entire wiring harness was melted and I had to rip it all out.

Lesson learned was the longer the wires run from engine compartment to lights, the heavier the wire gauge needed. Many of the high-end brands provide heavier wire with the higher amp lights they sell, but even if they do it still matters how far you extend the wiring. I replaced all my wiring with thicker gauge wire and solved the issue. You can immediately tell the difference by feeling the wiring after the lights are on for awhile. If the wires get warm at all, then the wire is too thin.

You probably already know that Aux 1 & 2 are the high amp switches, and Aux 3-6 are only 10 amps. I'm guessing the rear lights you added only need 10 amps, so Aux 6 should be fine. My other advise would be to never bundle the wires together and zip-tie them. Any heat the wires might produce is magnified when they're all touching each other (I've also made that mistake). Just cut the wiring to the correct length.

Glad your Bronco and garage and family are all safe!

 

[4x4TruckLEDs.com]

Did @4x4TruckLEDs.com replace the harness after a picture was provided?

Im not familiar with that persons order (need more info) but there’s always 2 sides to a story as you know - we probably offered a quick fix or replacement but never heard back about his pigtails…

as to the original post about a bad harness it should be know that is NO our harness being used but another company - I don’t want folks thinking our harnesses are bad as they are far from it - in fact we are known for having the best Quality harnesses around

 

[BigMex]

Im not familiar with that persons order (need more info) but there’s always 2 sides to a story as you know - we probably offered a quick fix or replacement but never heard back about his pigtails…

as to the original post about a bad harness it should be know that is NO our harness being used but another company - I don’t want folks thinking our harnesses are bad as they are far from it - in fact we are known for having the best Quality harnesses around

Important clarification: I purchased this from F150LEDs,
NOT 4x4TruckLEDs.

I’d been checking out your website and am interested in some front fogs and a harness to connect to my Badlands/Modular/Lux fog light pre wiring. I’ll be in touch with you soon.

I’ll post some more updates soon. I disconnected all the under hood wiring, cut the burnt wiring out, and after looking under some of the insulation, it looks like the short started where the switch wire and two pairs of cables out to the lights all hook into one of the plugs. Some better QC from F150LEDs or their supplier should have avoided this.

 

[Dom]

If the fuse didn't pop, then the current probably was'nt sufficinet to do so. Unless it was wired wrong (which probaby would've blown the fuse) the harness was not designed properly to handle the current going through it. Glad to see the only damage was to the harness. Your diligence was a Bronco saver. Good job.

 

[Navyicman]

So it looks from the picture that the harness wire is definitely a smaller AWG (looks like 18 AWG) versus the 16 AWG wire for the aux switches. 18 AWG is good for a about a max of 14 amps at 12 Volts DC in a raceway, 18 Amps in free air. In this case, the wire was acting as the fuse because the fuse itself is bigger than it should be. Why it didn't stop when the fuse was yanked was probably because the insulation was already broken down and you were conducting through the failed insulation. A miss wire or just poor construction of the harness contributed to this. Just my 2 cents, but my EE degree can back it up.

 

[KABQ]

A couple remarks. Yes, a longer run requires a larger wire gauge because longer runs increase resistance and therefore heat. The fuse was clearly too large an amperage for the wiring since the wires overheated before the fuse popped.

I know everyone likes to put sooooo many lights on their truck, but please understand how electricity works JUST A LITTLE BIT before you do it yourself. Even at 12V you can burn your truck to the ground. There are easy to use charts that show you what gauge wire you need for x current at y length in free air and in a conduit. This stuff is relatively easy. Use it.

 

[330SMG]

I thought of you @KRoyal080 …

A month ago I installed some rear-facing rally lights from F150LEDs, and enjoyed a day-long project of snaking wiring along the frame and hooking everything up just right.

A few times, the lights wouldn’t activate when I flipped Aux #6 and today I decided to investigate. It occurred to me that maybe heat under the hood had something to do with it.

With the engine running and switch #6 flipped on, I saw no lights so I popped open the hood.

The wires from the relay to the upfitter wire splice were WHITE HOT. I could barely hold them without burning my fingers! Had they been bare wires, they would have been glowing red. A minuscule puff of smoke emerged from the area near the splice. I quickly shut off both the switch and the engine, and the wires got hotter. I pulled out the inline fuse to eliminate current and turned around to search for some wire cutters when I heard a pop!

Alrhough there were no flames, billowing white smoke bellowed away from the wire bundle as both the insulation and the sheathing burst open. I was ready to run for the nearest fire extinguisher when I proceeded to clip the wires, cutting their connection to the battery (and hopefully the source for combustible energy).

I suspect there was a short in the harness I was provided. Although I’m an amateur electrician, all of my connections were installed correctly, and this case is beyond my ability to diagnose. I would have thought a fuse would have blown further upstream rather than cause a near fire.

Thank the Lord! I don’t want to imagine had it not occurred to me to pop the hood and troubleshoot things this afternoon…My Bronco was already in the garage and my family is home.

Below you can see the vendor-supplied splice connection and the quarter-inch length of Upfitter #6 cable I sacrificed to disconnect this firetrap.

I looked at the product and you do not need that relay or that switch to make it operate, it seems like your inexperience at wiring help cause this.
The aux switch can directly power these LEDs, my front foglights from Oracle are wired directly to the aux switch (#6 10 amps they only draw 6), they tell you to cut the relay and the switch off whe using Aux connection
I can't imagine that those LEDs take more than 10 amps, that is switched 3 through 6.if it is 15 use 2.


Here is few tips.
Don't use vampire clips on anything
Don't have big bundles of wire cut it to length.

When I add accessories I use heat solder connectors that are waterproof.

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