It's time to replace the wiring harnesses that run through the tailgate hinges. I have broken wires in both, with pictures at the following link:

http://krenek.smugmug.com/Other/240-pictures/n-5HkLX

I've purchased the Volvo OEM wiring harnesses from IPD and am ready to go. But the replacement wiring I have does not replace the broken wires I see in the hinges.

There seems to be some extra black wires running alongside the wiring harnesses. On the driver's side, there is one broken wire and the passenger side has 2 broken wires. Again, both of these are outside the wiring harness and are NOT included in the kits I received from IPD.

Are there other wires that run alongside the wiring harnesses? Where do I get these? Does this look like some type of modification?

I want to be prepared before pulling this apart because I this is a daily driver for my kids and their jobs.

Thanks for any pointers.

I tackled the job today and it went smoothly, thanks to all the help from the board members. A few things I discovered:

- a ladder works well holding up the tailgate. I did one hinge at a time and it worked perfectly.
- when pulling the harnesses, I attached a string so it was easier to pull the new harness through
- the driver's side of the tailgate was a PITA go get the harness wires pulled through. I ended up clipping the bullet connector off and reattaching a new one once I pulled it through. The passenger side was much easier and seemed to have more room to thread the wires.


Here are some pics of the morning adventure.

My ladder was not quite tall enough, so I improvised:



I had never pulled the headliner before, and it proved to be fairly easy. Great design:



The driver's side harness had been replaced by a previous owner, but had failed. You can see there is not much white sealant around the holes:



Here you can see the old harness after I pulled it through, with a string attached for the new harness:



Driver's hinge ready to go back in with both a new ground wire (blue) and harness and black crap:



This is the underside of the passenger hinge. The extra wire mystery is explained. A previous repair for the broken ground just added a pair of ground wires with a couple of bolts through the hinge ribs. No black crap in their either so I'm no sure how the water stayed out. I stole some from the tailgate for the reinstall:



I drilled a small hole in the metal to attach the ground so it would be hidden by the headliner. I did this on both sides:



And I secured each ground wire to the grounding points in the tailgate:





That's all. Everything I could test worked great, including the center light and wiper. It should not be long before we get a good rain and I see if the hinges sealed back up properly.

Thanks again for all help.

Thank you for the pointers. I now see the extra thick black wires are ground wires attached to the hinges. I plan to replace the wire with some #13 test lead wire since it's meant for this type of application. I may either pry the hinge crimps apart as Art did or run the ground wires into the roof and tailgate and find attachment points inside those places.

On the passenger hinge, there is a smaller single black wire that is broken. I think this could be the center brake light wire, as this was probably an US-specific modification. Thanks Derek for pointing this out. I'll probably need to get a smaller gauge wire than the #13 I have so it fits through the hinge and holes.

I plan to remove the tailgate and hinges, clean things up nicely and put it all back together.

What is the best way to ensure I don't have any leaks where the hinges attach to the roof and tailgate? Do I need new gaskets (hard to find?)? Special kind of sealer?

Thanks again for all the help.

I'd say since you are going to be back in there doing this again in half dozen to ten years or so depending how much you use the tail gate. I would go with something less sticky.

I used duct sealing compound that I got out of the electrical department at a Ace Hardware store. Its very reasonable for a big gob or loaf of it. Made by GB electric in the USA!

PACK a bunch of that stuff anywhere you have an opening and it will squish down and move out any excess.

I live in Up close to Oregon and get a fair amount of rain and so far it has worked for me for two repairs without leakage. Main thing it's not sticky and I think the harness has a better time living with it.
Also, I took my rotary grinding tool and routed back an edge that the wires have to bend out and around.
I think I moved that edge back close to about 3/16 of an inch to provide more arc and flex room in the bend zone. Its casted out just a bit too far, IMHO.

If you play with the hinge you will see where you can make the adjustment. If you have the right size mounted stone you can widen the channel a wee bit along one side too.
The more the hinge can move without tugging or holding the wires tight the less tension is provided.

You can pack some insulation compatible silicon grease through a tiny slit or puncture in the sheath near the area of the flex. Since you bought an aftermarket harness you might use a plastic syringe from some electronics outlet.

Once everything is bolted down the wires are pretty much stuck there. Working on the idea of no pulling or being stretched over an extended inner edge helped me.

I came up with these ideas on my last repair so its under evaluation for at least two years now using regular wire.

I have read of a source that makes a special insulation on stranded wire for bending purposes but their minimum order, was on the order of a trip to the moon, for me!

I would have to hang outside their back door and hope for scraps of the line. Having those thrown into a dumpster invites diving days back! (:-)
Thinking about that, it would be rather conspicuous of me to carry a short step ladder. I would break my fool neck trying to use a shopping cart and act homeless! (:-)
There is No wondering why I bought 16ga. and 18ga. wire and lightly heat shrank my own harness together!

Phil

the tailgate is VERY heavy and awkward.
imo you will be better served to do one side at a time leaving the gate attached on 1 side with a board propping up the unhinged side.
also leave the gates struts alone as they help stabilize the gate during this procedure

And wear some gloves fooling around with those hinges so you won't get that black butyl rubber on your pristine headliner.




--
Art Benstein near Baltimore

Blowing out another's candle will not make yours shine brighter.

Unlike Ted, I have seen the effect of omitting the ground wire in the repair.

But not from the driver's seat. About the only way you see it is when following the wagon, the license plate lights wink as the car encounters imperfections in the road surface.

May not be important, but it seems worth my time to repair the wires -- although I recognize there's no IPD plug-and-play solution short of new hinges.





I picked the crimp apart and put a new piece of wire back in the crimp, rather than trying to replace the staked terminal. Soldered.




--
Art Benstein near Baltimore

By the time a man realizes that his father was right, he has a son who thinks he's wrong.

Being as yours is a late car it should have wires in the harness for the tailgate window brake light. This wasn't fitted for all markets so you may not have one. A "universal" replacement harness should have them included.

the black wires to which you refer are short and create a ground between the both sides of the hinge and the cars body.

they are riveted into each side of the hinge as you will see.

i seldom bother fixing this wire when i redo the harness's and to date has not made a difference.

also rather than buying new harness's it is much cheaper and easier to splice lengths of similar gauge wire using butt connectors and a GOOD linesman crimp tool.

this way you add an extra 8 inches of wire and be ready for the next time it breaks

To ad to Uncle trichard's good comment, please use appropriate gauge wire comprised of a braided conductor and an insulation meant for outdoor exposure such as those conditions the factory install wire harness was made from. (Though modern materials are more durable with a longer service life.)

Braided copper or copper alloy is fine. Some may use braided stainless conductor. Braided conductor better withstands recurring flex and vibration over straight (not solid), or stranded conductor. IIRC, the wire gauge is 12 or 14 gauge?

You may further want to add an outer sheath.

The ground cable you see is the same or a gauge larger than the + VDC power wires for the taillights, wiper motor, and rear demist grid.

At this time you may want to inspect the rear hinges, if they are original, for sag. The rear half of the hinge, at and after the hinge pin, will appear to sag and may even rest on the roof. There is little to do but to replace both rear hatch hinges. You may get lucky at a junkyard and find a replacement set of rear hatch hinges with newer synthetic rubber gaskets. Some butyl rubber under and on top of the gaskets where the hinge rests can help seal the assembly to moisture intrusion.

Questions?

Hope that helps.

cheers,

Buttermilk MacDuff.
--