For the next guy/gal - Headers and melted wiring harness

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Ftera

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So i was out on a barstow to vegas run when en route there the check engine light came on? Mike S used his handy bluetooth obdII scanner and the code read p0133 (low voltage bank 1 02 sensor). Truck ran all the same so I ignored it. What else could I do.
Later on down the trail the check engine light went away. I was like ok.

Now coming back from vegas to barstow is when all hell broke loose. I initially got the check engine light but no difference felt driving.
At that point I had my locker engaged.
About a mile down the trail it happened. Tool icon lit up, hill decent fualt, service atrac and the truck went into limp mode.

Im still learning the ins and outs of these trucks so I called it a day and limped it home. That was not much fun. Good thing Jeff from SVC found me on the freeway, checked some things out but we could not figure it out so he escorted me as far down the 15 as he could. Thank you Jeff and SVC.

Went home and started reading all kinds of threads. Quickly I figured out to go check fuse #76 under the hood. Sure enough it was blown. Changed it out and truck ran fine with only the check engine light on and code p0133.

Took the truck to the dealer and they claimed it was a bad 02 sensor and they changed it under warranty even though I had lth. I pointed out to them that the harness was laying on my header but they said it was OK and sent me on my way. No not check engine light once I picked her up but I still knew something was not right. Something had sorted fuse #76 so I took her in to have the harness checked out.

Conclusion: The wiring harness was melted. The one that leads to the tranny and controls 4wd system, locker, 02 sensors and whatever else from the ecu passenger side. It was destroyed.

No fixing that one. So, I had a harness emergency mailed from Detroit and swapped out. Problem solved.

My suggestion to anyone running lth or not, is to check your harness and perhaps use extra ties and double heat shield wrap it. Its a weak link. Also, if this happens to you on the trail, 1st thing is check fuse #76 and replace fuse if burned out. Then check to see if your harness is contacting something hot like your headers. In a pinch move it and secure it. Dont use your locker or 4wd system as there is the possibility as was my case that by doing so and the wet conditions it shorted and that is why my fuse blew.

I hope this helps anyone that may experience something similar and what to look for to get out of a false limp mode a make it home in a better fashion than I did.
 
D

Deleted member 12951

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Maybe a stupid question but what is Running lth?
And so I don't have to run out and get the manual, what type and size fuse is #76 to carry one on trips?
 
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Ftera

Ftera

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Joined
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Maybe a stupid question but what is Running lth? And so I don't have to run out and get the manual, what type and size fuse is #76 to carry one on trips?

Long tube headers

---------- Post added at 08:47 PM ---------- Previous post was at 08:46 PM ----------

That's just a tad blurry....
How's the second pic?
 
D

Deleted member 12951

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Long tube headers

---------- Post added at 08:47 PM ---------- Previous post was at 08:46 PM ----------


How's the second pic?

Yellow, is that 20a?

Did they cover that under warranty being replacement headers, if they said that is what caused the issue?
 
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