Wiring issue fault: Cause/solution... for the next poor soul

Beardy · **Joined:** Wed Dec 16, 2015 4:38 pm **Posts:** 8

Hi All,

I have had a 2005 (2006 loom) fail and blow fuses 26 and 16. It started as an intermittent problem blowing fuses occasionally and got worse to the point of not starting at all. I went though the wiring schematics and it seems to be a 2006 loom. Then I removed (unplugged) all the parts that I could in an effort to isolate the fault. The car only blew fuses when it tried to start. I had the ECU checked (many thanks to Keith at GDE), and also checked for potential chaffing and issues behind the fuel filter (that seems to be common). However, eventually tracked it down to the loom rubbing on the alternator bracket that goes from the rear of the alternator to the intake. A combination of casting flash and machining had caused a sharp edge that had cut into the loom and it was sparking to ground. Although the loom looked worn it did not look significantly damaged from an external examination and it was only when the covering was removed could I see the burn marks and result of arcing.
Removing the bracket to clean off the sharp edge and repairing the loom seems to have cured things (until the next time).

drive safe.
Beardy

GordnadoCRD · **Posted:** Thu Feb 09, 2017 1:09 am

Glad you got it taken care of.

I just recently gremlin-proofed mine at that spot. I used a section from the handle of a shoehorn as a backbrace for the loom where it passed the brace there, zip tied it and taped everything over.

Since then I've found some stuff that has changed the world for me regarding wiring looms.

http://www.gates.com/products/industrial/industrial-hydraulics/accessories/polysleeve-wrap Poly sleeve Wrap by Gates and other imitators is a product made for wrapping and protecting hydraulic hoses on heavy equipment. It works perfectly for wiring looms. I found it in 7/8" which I used on the 1 1/2" loom where it passes over the rear of the engine compartment from the center Y to behind the coolant reservoir. You just stretch one end out till it passes over the loom, and start spiraling it on. Need to do maintenance there or put in a new wire or whatever? Just spiral it off, and use it again when you've finished what you were doing! It's strong and way more heat resistant and abrasion resistant than convoluted tubing, and the 3/8 stuff will go up to 7/8" I believe the 7/8 stuff can probably go to 2".
Any place that does hydraulic hoses should carry it. Gates says they make lots of sized and 2 colors, but I only found the 2 sizes, and a ton of colors including neon pink green blue.... Check around for hydraulic hose spiral poly wrap if you need to re-loom something. It's cheap too.

WWDiesel · **Posted:** Thu Feb 09, 2017 1:11 am

You are not the first to have experienced this problem, there have been others...

Anyone with a Jeep CRD should check and redo the wiring loom for this harness where it runs behind the alternator bracket!

See this thread where another had a short in the same location:> viewtopic.php?f=5&t=84861&hilit

After his find, I redid my harness cover completely!
Plastic wiring loom covers are CHEAP!
The old plastic protectors were very brittle and would break or crack if you moved them much or where they had rubbed up against that metal bracket ... :roll:

Picture of updated harness cover:

Beardy · **Joined:** Wed Dec 16, 2015 4:38 pm **Posts:** 8

follow up

Alternator output now massively overcharging. I think br/dg wire that goes to alternator that was damaged and shorting to ground (and happened along with the br/pk that was the things that blew fuse 16-original symptom) and according to the 2006 wiring diagram this is the rectifier control wire that goes form the BCM / voltage regulator to the rectifier and then to ground. It is this wire that controls the voltage output of the alternator.
I noticed the smell of sulphur and sure enough the battery was hot and so I turned all the electrics on and crawled back home in the hopes of pulling the voltage down and keeping the alternator speed low. However, battery swollen and seems effed.
I am assuming that the grounding against the alternator bracket blew the output stage of the BCM voltage regulator circuit but perhaps it took out the rectifier??
I suspect the next step is to pull the alternator off and get it checked and probably buy a new BCM.
Any advice ?

Wiring issue fault: Cause/solution... for the next poor soul

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