Burned up wire and batteries

rreegg

Full Access Member
Joined
Feb 10, 2022
Posts
242
Reaction score
141
Location
Puget Sound
Ugh lol, went out to the truck earlier and noticed the dome light didn’t turn on. Ultimately found there’s a burned up positive wire, probably 14gauge connected to the passenger side battery. And both batteries are dead at like .1V

Not quite sure how this happened.
Haven’t traced this wire to the end yet but seems like it routes toward the rear of the bed.

Last time I drove the truck was about a week ago after installing a tow receiver. My assumption is a wire must’ve gotten clipped or something and it fried during the drive. The corrosion is just from it being wet this past week.

Shouldn’t be much a problem to fix this but want to make sure it doesn’t happen again. Any ideas? This positive wire, whatever it does, could probably use an inline fuse. Will check if any other fuses are blown. And replace stuff I guess. Would assume the batteries are done for but will try and see if they hold charge.. not really familiar with batteries burning out like this.
 

Attachments

  • 73539145-10BD-4E40-8D37-0FD7C873BB75.jpeg
    73539145-10BD-4E40-8D37-0FD7C873BB75.jpeg
    301.1 KB · Views: 18

Noiseydiesel

Full Access Member
Joined
Jan 17, 2019
Posts
609
Reaction score
257
Location
Hillsboro, Ore
Since the vehicle was off and burned the wire, you have a live short to ground.
Install the inline fuse while replacing the wire. As you inspect/replace the wire look for an obvious problem. Double check that receiver wiring. 4 wire or 7 wire?
Chances are it's a 7 wire and the only question remaining is how you wired it?
RV style or other? Take apart the connector and see if a few wires got too close.
Charge the batteries on a charger. DO not jump them and let the alternator charge them.
THAT will kill the alternator. Alternator is designed to keep charged batteries charged.
Finally after the batteries are charged, install that fuse or better yet, put an amp meter in the line and see if it has any draw.
Best way to do that is install a 7.5 amp fuse on the pos lead of the multimeter. Set the meter to the 10 amp setting and see what you get. IF it is above the 7.5 amps, it will blow the fuse on the probe wire going to the meter and NOT the fuse inside the meter.
 

rreegg

Full Access Member
Joined
Feb 10, 2022
Posts
242
Reaction score
141
Location
Puget Sound
Thanks for the tips, interesting technique to put a fuse on the multimeter probe!

Should have been more specific on the initial post but I didn't intentionally edit or touch any existing wiring at all. There were a few wires around where I (carefully) drilled holes for the receiver but otherwise that's close as got to them. Regardless, last I remember there being a 7 pin pigtail for the tow harness.
I'm not sure the wire burned while the truck was off but that's probably moot (and why we'd want to check for current on that wire after replacing anyway).

Will take a more thorough look tomorrow and update if anything is super crazy
 

Olds64

Registered User
Joined
Nov 13, 2022
Posts
65
Reaction score
16
Location
Edmond, OK
Does the truck still run and operate since that wire burnt down?

I suspect it would have been for a trailer coupler that was just installed incorrectly. Look under the bed at that 7 pin coupler and you might even find some wire nuts there.
 

hacked89

Full Access Member
Joined
May 30, 2018
Posts
1,766
Reaction score
2,358
Location
Bucks County PA
As you know, that looks like some hack wire that a previous owner added. Let me know the color code of the factory wire that it’s spliced into and I can help you more.
 

rreegg

Full Access Member
Joined
Feb 10, 2022
Posts
242
Reaction score
141
Location
Puget Sound
Yaaap, looks like i smooshed a wire under the receiver bolt.
This specific one took a little more fiddling than the rest because I was missing some spacer hardware from the factory and had to roll my own. Oh well so much for being careful haha

The hack wire is spliced into a yellow one which must be the always on power for the receiver
 

Attachments

  • 1E4EE608-46C5-411B-9C4A-EF86D329069F.jpeg
    1E4EE608-46C5-411B-9C4A-EF86D329069F.jpeg
    306.6 KB · Views: 7

rreegg

Full Access Member
Joined
Feb 10, 2022
Posts
242
Reaction score
141
Location
Puget Sound
I’ve been under the impression that once a lead acid battery completely loses voltage it’s Done-zel Washington. Have one of them on the charger now but am doubtful.
This is all basically non-required wiring so hopefully it’ll be fine after the battery situation is sorted out; nothing else looks too melted
 

hacked89

Full Access Member
Joined
May 30, 2018
Posts
1,766
Reaction score
2,358
Location
Bucks County PA
I’ve been under the impression that once a lead acid battery completely loses voltage it’s Done-zel Washington. Have one of them on the charger now but am doubtful.
This is all basically non-required wiring so hopefully it’ll be fine after the battery situation is sorted out; nothing else looks too melted
You got the wire sorted. As for batteries, I’ve brought them down to zero multiple times and back to life. There’s a chance it’s done but most of the time I’ve brought it back. The one thing that does happen every time is it loses its polarity. I have to hook a good battery up to the dead battery with jumpers and then a trickle charger on it at the same time. That’s how I bring it back.
 

rreegg

Full Access Member
Joined
Feb 10, 2022
Posts
242
Reaction score
141
Location
Puget Sound
Good to know they’re still chargeable, ended up just replacing them under warranty as it’ll at least save some time probably
 

Noiseydiesel

Full Access Member
Joined
Jan 17, 2019
Posts
609
Reaction score
257
Location
Hillsboro, Ore
Smooshed-ded the wire. Glad you found it.
Bringing back a stone dead battery can also be done in the vehicle if you want to cheat.
Hook up the charger and turn on the park lights. Park lights get current flowing and after about 10 minutes, turn off the lights and let the battery continue to charge. Battery out of vehicle? Hook a test light across the terminals to make current flow and start charging.
PS. You also should replace that entire wire. Hopefully it did not go inside a harness along the way.
If it did, take apart the harness and fix it all.
 

Latest posts

Forum statistics

Threads
91,257
Posts
1,129,303
Members
24,082
Latest member
Bsthomas21
Top