Don't burn your truck down!

[carbon60]

I was driving down a dirt road, yesterday, when I noticed the telltale smell of hot plastic. By the time I had the truck stopped, a USB cable plugged into a rechargeable camp light was smoking. Really smoking, like enough to be hazardous with the windows up.

The cable had come completely apart at the connector and was about to catch fire when I unplugged it. :Wow1: I don't know if the cable failed because of vibrations, or was simply faulty. It was a few months old.

So, I'm going to measure the current requirements of all my small stuff (phones, tablets, lights, etc) and replace the fuse on that circuit with a much lower rating. In my rig, that circuit is always hot so my tablet stays charged.

Beware!

A.

 

[fog cutter]

that's too close. i wonder when i see build threads just how correctly integrated some of the plumbing and wiring systems really are. at least with plumbing you can change clothes and eventually things will dry. 'tricity something else altogether. don't think i'm the only one with this perception:

"5) Isolate and Minimize All Electrical Modifications:
 Electronics are the bane of all travelers, taking more time and requiring more “fiddling” than any other system. The reality is that most modern travelers do use and often need electronics to enhance their experience, including digital cameras, GPS units and laptops to record their story. However, miles of wiring and fuses and connections are some of the most common failures. As a result, completely isolate all “house” electrical systems from the factory harness and use a dual-battery system and auxiliary battery to protect starting voltage. Spend the time or money necessary to ensure the wiring is 100% correct, including quality components, weather-tight connections and proper fusing. Electronic gadgets are so appealing that they often waste tons of time and create major distractions to the driver. Save the flip down monitor and triple iPad infotainment system with surround sound for Hollywood."

from here: http://expeditionportal.com/the-10-commandments-of-modifying-an-overland-vehicle/

 

[Charles R]

Also make sure your connections are clean, and have good contact pressure. There is another way electrical connections fail, called "thermal runaway".

This happens when the resistance of a connection or component goes up, due to corrosion, contamination or just being a bit loose. Resistance creates heat, and heat creates resistance. And the thing goes into a feedback loop until it burns up or goes electrically open. The dangerousness is increased because the amperage actually goes down a bit, so it won't blow the fuse to stop the process.

This process is also accumulative. Each time the connection cooks itself, the "base" resistance gets higher. This then gets the process ramping up quicker and quicker each time the circuit has current flow.

So always periodically check your wire connections for signs of heat damage, and remember that it's not automatically too much current that caused it.

 

[Co-opski]

Also make sure your connections are clean, and have good contact pressure. There is another way electrical connections fail, called "thermal runaway".

This happens when the resistance of a connection or component goes up, due to corrosion, contamination or just being a bit loose. Resistance creates heat, and heat creates resistance. And the thing goes into a feedback loop until it burns up or goes electrically open. The dangerousness is increased because the amperage actually goes down a bit, so it won't blow the fuse to stop the process.

This process is also accumulative. Each time the connection cooks itself, the "base" resistance gets higher. This then gets the process ramping up quicker and quicker each time the circuit has current flow.

So always periodically check your wire connections for signs of heat damage, and remember that it's not automatically too much current that caused it.

Wow thanks for the information.

 

[fog cutter]

there's a bunch of good videos for the (like me) neophyte here: https://www.youtube.com/watch?v=Zd8af95HK68

 

[verdesardog]

Also make sure your connections are clean, and have good contact pressure. There is another way electrical connections fail, called "thermal runaway".

This happens when the resistance of a connection or component goes up, due to corrosion, contamination or just being a bit loose. Resistance creates heat, and heat creates resistance. And the thing goes into a feedback loop until it burns up or goes electrically open. The dangerousness is increased because the amperage actually goes down a bit, so it won't blow the fuse to stop the process.

This process is also accumulative. Each time the connection cooks itself, the "base" resistance gets higher. This then gets the process ramping up quicker and quicker each time the circuit has current flow.

So always periodically check your wire connections for signs of heat damage, and remember that it's not automatically too much current that caused it.

Yep, what he said^^^^^

 

[Charles R]

Let's see if this link works...


This is a shining example of thermal runaway. This fuse still passes current, and is not blown, but you certainly can see the heat that it has been creating.
I just recently replaced another runaway case, where the spade connector 'crimp-to-wire interface' was the culprit.

 

[fog cutter]

link doesn't work for me :ugh:

 

[GregSplett]

When I was just out of high school I had a job installing car stereos.One day I crossed the two terminals of a cars battery with a 10 mill wrench.Melted the wrench in half within seconds.Good lesson young.