My kid recently bought a 2001 Grand Cherokee Laredo. Yesterday the driver's door electrical suddenly quit working. I suspected loss of either the 12V, or ground connection and when I determined the ground was open-circuited, I searched for most likely locations. It seems the broken ground in the flexible bundle to the door IS now infamous.
From my work in factory automation, I know that copper wires and flexing are a bad match. Robotic cables are made with many very fine copper strands of copper in more flexible insulation - engineered for long life in flexing applications. Even then, there is a strong attempt to prevent any kinking of the wires, because that becomes the point of failure. (Think about how you can bend a loop in your tape measure and roll that loop, to get your measurement - but if you kink the tape, it cracks and soon breaks (or you get tired of cutting your fingers on it).
I found that my kid's Jeep had been repaired once before, when the black wire to the driver's door had failed about 2" from the front entry to the door - the wire broke at one end of the butt-splice. My guess is that that is the same for most of these failures (whether the black (chassis-ground), or the grey/orange (12V) [both are 12AWG wires, while all the other wires are a much finer gauge - maybe 18 or 20 AWG and more flexible.])
After pulling the rubber boot and connector through the opening in the kick-panel, I spliced a new wire to the remaining stub of the broken black wire, using a butt-splice with heat-shrink tubing (meant for outdoor environments) [ACE Hardware carries GB brand waterproof butt-splices (stock number AMT-126), at qty 3, for $7, or Home Depot has the AMT-4126, qty 5, for $4.48]. The shrink tubing provides protection from water (which can also include corrosive road salts) and also provides some strain-relief on either side of the splice.
Then I butt-spliced the new wire inside the passenger compartment, leaving a small loop, which can more freely slide as the door is opened and closed.
Next I wrapped the bundle of wires with electrical tape, from the door-end, to about 3" from the door, to help prevent kinking in that same area of the wires - this may push repeats of the problem to another part of the wires, or may cause the entire bundle to slide into and out of the kick panel; either way, hopefully delaying repair / replacement of the wires.
Failure of wires which repeatedly flex (e.G. Wheel-speed sensors) is not unexpected - hopefully the auto industry learns from these common failures and changes their ways. There is no perfect vehicle and I do not look forward to having to own a "drive by wire" vehicle.
Thank you for the helpful info on your website.
Thursday, July 22nd, 2021 AT 6:36 AM