Cracked wires in the door hinge area

[6spd_monte]

For a few years now my power locks have been slowly getting weaker and weaker. I have to hit the button two or three times to get all the doors unlocked. Only the fronts, the slider and barn door locks work fine. When I installed a GM accessory keyless entry kit it got worse. I was able to figure out that I was loosing voltage somewhere, I only had six or seven volts at the actuators in the front doors, but I couldn't find where the voltage was going. I thought it was a poor ground somewhere but I could never find it. Eventually I gave up and put the project on the back burner.

Fast forward a to February 2011 and a little accident caused me to strip the entire van down for paint and body work. I even removed the body harness and door harnesses. I noticed that on one front door one of the ground wires had been spliced and run to a sheet metal screw into the door shell. I thought: "Hmm, that wire must be broken in the flexy part near the door hinge. The shop my parents used to take the van for service must have done this before I started taking care of the vehicle." Then I thought: "Holy crap! There's probably more wires damaged in there and that's probably why my locks are lazy!"

I don't know why I never thought of it before. It's the obvious answer, both front doors have problems, on an old vehicle... Anyway, I stripped the driver's side harness open and this is what I found:

The insulation is cracked but the conductors are not yet broken. This allowed humidity to get into the wire and cause corrosion all over the copper conductor, severely limiting its current carrying capacity.



Here's a closer look. Digital Macro!



Here's how I fixed it. I went out and bought a bunch of new wire, I matched the colors the best I could.



I made detailed notes about which wires went to which position, which connector they went into, and if I couldn't match the wire color I noted what the color changed to. Some colors are duplicated in the harness so I marked them with tape so I wouldn't get them mixed up.
Then I measured, and cut nearly two feet out of the harness!



Next, I spliced...



Soldered...



And heat shrinked the repairs.



So that it would be well sealed and moisture couldn't creep in and cause problems again, I used this fancy shrink tube that oozes some kind of goo when it shrinks to seal it up nicely.



Here's the harness all repaired:



Taped up again:



Flexy boot installed:



And done, with the connectors installed. Good as new!



If you're wondering why I cut and replaced so much of the harness, there were two reasons.
A) The corrosion had spread pretty far up the wire. It was at least six inches on either side of the crack before I found clean copper.
B) A solder and heat shrink repair is not very flexible at all, and the old wires are pretty stiff as well. I was concerned that if I made the repair right in the middle of the hinge the old wires would soon crack again near the repair. So, I planned it out so that the repairs - two in each wire - would be in and area that doesn't move when the door is opened and closed.

I'm pretty excited to have good strong locks at all the doors. But, I haven't gotten to the stage where I can reassemble the doors and put them back on the van, so unfortunately I don't even know if all this actually worked!
I'll let you guys know when I find out.

[MountainManJoe]

Good work. I should check my door wires too.

Hmm.. I wonder how GM could have prevented this problem...

[lockdoc]

Nice repair done right! I have had a problem with those wires in a few vans. Difference with mine was that I had the complete opposite problem. The wires broke INSIDE the insulation. I found the breaks by checking which wires stretched when pulled.

[okie1]

Very nice repair, done properly & nicely documented. Well done.

[CaptSquid]

Smart move on your part, cutting out past the corrosion. You'll have fewer problems that way. Electrical cancer is hard to cure, just like body cancer.

[6spd_monte]

Good news! I finally have the doors installed on the body again and I am pleased to report that the locks are working normally!

Hooray!

[MountainManJoe]

What is this heat shrink tubing that you used?

[Smiliesafari]

Nice write up, James. Another job well done.

[Astrophysics]

Nice work. Looks like total of 10 wires. With that number of wires to splice, sometimes it is a good idea to stagger the location of the splices to avoid a bulge in the wire bundle.
Also, use regular tin/lead solder not the new lead free solder that is cropping up at hardware stores and electrical parts places.


Astrophysics

[6spd_monte]

What is this heat shrink tubing that you used?

It's sold at your local BMW dealer. The part number is 61-13-1-379-833. It's kinda pricey through the dealer (no surprise) so I'd recommend looking online for a better price.

Nice work. Looks like total of 10 wires. With that number of wires to splice, sometimes it is a good idea to stagger the location of the splices to avoid a bulge in the wire bundle.
Also, use regular tin/lead solder not the new lead free solder that is cropping up at hardware stores and electrical parts places.

You are correct, especially with that shrink tube I used. It's a bit bulky so there is quite the bulge in the harness where the splices are. I got lucky and the extra girth didn't cause any problems, but spacing them out would have been a better plan.

Why do you prefer the tin/lead over lead free solder?

[MountainManJoe]

Thanks.

I also find the lead solder is easier to work with. It has a nice shiny finish that tells you your joint is good. When lead-free solder cools, it becomes dull and looks like a bad joint. It may not be, but how can you tell? Also, lead free solder melts at a higher temperature, so it's harder on your tools. You'll be replacing tips more often.

[MountainManJoe]

You can also buy things called solder sleeves. They combine your heat shrink tubing, adhesive lining, and solder paste into one piece. All you have to do is insert your wires and heat!

[safari kev]

I have had problems with my front doors as well. (which have been my biggest gripe about the van)
my drivers window only works about 97% of the time.
my drivers lock switch does not work at all (replaced switch with known good one- still have problem). remote still locks and unlocks door.
my passengers lock switch will not lock about 10% of the time. the power lock button is also weak. It unlocks fine though. (switch has been replaced with known good one and problem persists)
My GM remote locks all doors, except the passengers door about 5% of the time.