To remove any doubt on this topic, the quality of the wiring that runs to the rear doors is very low. I had intermittent speaker issues in the rear of the quad cab and so figured that after 5+ years the cheap factory speakers were done. I dialed in Crutchfield and ordered new ones for front & rear. After install I still had poor, intermittent, or no sound. I suspected my aftermarket deck so went thru the hassle of pulling apart the front (which inevitably causes a ding here & there to the paneling) but the deck and wiring was fine. Upon opening and closing the rear door I then noticed changes in sound. I sliced open the hinge wiring channel and found many wires that were cracked, some completely frayed, and even one with electrical tape covering a broken wire. Yes, this is from the factory!!! I am the original owner and the channel had never been opened, yet there is electrical tape on a frayed connection. Unbelievable. I had the tedious chore of stripping and reconnecting many wires, and I can bet that, while I'm at 117K now, over the next 200K there will be many a low quality wire that cracks etc. Argh.

 

I found the exact same thing in my truck while installing aftermarket speakers.

 

Yep, and it is a real tedious chore requiring micro-fingers to fix each. And then who knows what is beyond either end...the area in the door or in the door jambs that has crumbling wire. If I had a free weekend to inflict pain upon myself I'd re-wire the whole thing.

 

I need to rewire my second door on my 06 3500... I did the first one last year when the power lock stopped working, now the same issue happened to the other side.. When I repaired the first side, I bundled the cables together to make it less 'bendy'... possibly last longer.. we'll see.

 

Actually very common to find broken or damaged wires in the door boots. Most guys find it like with when they get no sound or not door locks