Rear diff lock harness wire break near clamp. Common failure?

[Caaarlo]

Hi,

About two days ago, I noticed that my rear diff lock was engaging properly, but the indicator light kept flashing.

After checking the engagement detector switch, I found that the light would stop flashing depending on how I moved the wiring. After further inspection, and after pulling the wiring out of the corrugated flexible tube, I discovered that one of the wires was cut internally right where it joins the plastic S-shaped clamp. It’s one of the two wires connected to the engagement detector switch.

This was most likely caused by fatigue from the flexing involved in rear suspension travel/movement. I’m wondering if this is a common issue. I haven’t fixed it yet, but I took a picture of the cut wire.

 

[Caaarlo]

Update: I unwrapped the harness at the S-clamp and found that most of the wires have cracked insulation. At this point it’s a vicious cycle: the more the insulation breaks down, the more the bending gets concentrated right at those spots.

Honestly, I wish Toyota had put a connector on the chassis side so this short, high-flex section could be replaced as a service part.

This is what the wires look like after some cleaning.

 

[excessive]

Good find. i guess age, heat cycles, the elements, and vibration / strain over decades have taken their toll.
i accidently burned my rear e-locker wiring harness when i was torching the upper shock mounting bolt. So i am dreading how I am ever going to fix that...

 

[Caaarlo]

Oh that's terrible, Yo will have to fix not only the rest of the wires but also the breather tubing.

Regarding mines... they "only" lasted 22 years and 340.000km of mud, sand rocks, water and vegetation