Solved! 04 V70; Brake lights don’t work, position lights stay on with ignition off Topic is solved

[Vova585]

That's great information. I would sure do those test with voltmeter first, but if everything will check fine with voltmeter I would use substituted load to see if wire is capable of carrying enough current(probably small marker light bulb or old fashioned test light probe. Another possibility to try open the back of the rem and inspect for any oxidation or signs cracked solder joints around relay at question or burnt shunt.
Thank you for bringing us along

[- Pete -]

Well I found some crispy wires finally. Didn’t occur to me that I’d have to look up into the sheathing where they are completely protected to find where they’d gotten hot to the point they then became crispy. I tried to upload a video but was unsuccessful. Here’s a few photos.

Would it be simplest to chop out good a section from a junkyard car & splice it in here?

I have a feeling I’ll need to brush up on my less-than-remarkable soldering skills …

I need to pull up in ViDA where it talks about what are suitable solders to use.

[Vova585]

Congratulations on this find. I am still surprised that all those fuses and shunts were not able to prevent this disaster from happening. I would prefer to replace that harness all together if possible to obtain from donor car(? If there is damage under portion of wire with still intact looking insulation). If such option would not be available I would prefer to use crimp and seal connectors with heat shrink wrap(usually advertised as marine grade. I think I bought from Amazon haistronica or something like that brand) for all the wires but the CAN twisted pair. Here I would try to find long donor section(if possible I would try to gently remove pins from donor car and slide them into your harness plug(this way you will only be soldering at 2 points and not at 4 which would minimize chance of disturbed signal).

[- Pete -]

Congratulations on this find. I am still surprised that all those fuses and shunts were not able to prevent this disaster from happening. I would prefer to replace that harness all together if possible to obtain from donor car(? If there is damage under portion of wire with still intact looking insulation). If such option would not be available I would prefer to use crimp and seal connectors with heat shrink wrap(usually advertised as marine grade. I think I bought from Amazon haistronica or something like that brand) for all the wires but the CAN twisted pair. Here I would try to find long donor section(if possible I would try to gently remove pins from donor car and slide them into your harness plug(this way you will only be soldering at 2 points and not at 4 which would minimize chance of disturbed signal).

Thanks. Yeah the CAN wires I am most concerned about. Concerned as in, I fear my repair skills may be too subpar to successfully perform a long-lasting surgical repair on those. I have to admit that I really don’t understand enough about the CAN portion, other than it carries signals moreso than voltage? If replacing the whole length is the best option, I then think about how much more of the car I’ll need to dismantle to replace the entire length of them & that isn’t less than daunting. They clearly were close enough to the heat to have their insulation be compromised.

I have some evaluating to do, but it is a relief to finally find what looks like the main contributor.


Vova, what was the situation you ran into where you were needing to repair the harness going to/from the rear of the car?

[Vova585]

I never had a need to repair such harness on my car. Given my car is 01 with 300+k wiring issues are happening here and there so I had to look into the reliable way to fix the problems(i am not great with soldering iron too). Through watching too much of "car porn" as per my wife, I learned what leading professionals in the field are using( SD, SMA, PHAD) in repairing customers cars.
I would also probably would be less than inclided to remove half of the interior(old plastic) to replace that wiring harness all together. That's why I thought removing twisted pair CAN wires with pins from connector to REM of the donor car would be best option. You would then have to solder them only in 2 locations(where attached to your car intact CAN wires). If soldering is not a "love labor" I saw some connectors with "solder seal wire connectors" which might be a sutable alternative. I heard they were not as durable as soldering, but given location and some good Tesa cloth tape on top they should last long. https://www.amazon.com/Connectors-Haiss ... 0778&psc=1

[- Pete -]

As it turns out, upon further dissection I have realized that replacing the entire rear loom will be the simplest, longest lasting & least labor intensive option. I will find a donor vehicle & harvest the complete rear harness & replace mine with it. I’ll need to take the entire REM & it’s surrounding fuse/relay block/ power distribution junction as it will just be easiest. I don’t mind paying for it & having it be done right all in 1 fell swoop. Surely splicing in sections of new wire would be cheaper … but I’d rather not ever have to revisit it if replacing it in its entirety gives me the best odds of that.

I will try to remember to take photos & update along the way. That’s one area in which I always & unfortunately fall short.

Thanks again for listening, for hosting this topic & letting me ramble.

[- Pete -]

In conclusion, replacing the entire rear harness was surely the way to go. I sourced one from a local pick & pull yard for about $47 USD. As I was installing it I also wrapped all exposed portions of it with high temp electrical cloth tape (thanks for the suggestion by Vova).

Aside from pouring over the car for the last 15 months, the most time consuming part of the electrical repair was removing the entire (rear) interior. Basically all but the roof liner came out. Quite a straight forward and almost therapeutic exercise as it offers a great opportunity to clean all the junk that falls from small hands & finds its way through the cracks.

The most frustrating part was not being able to openly see the wires that had literally fused themselves together since they were several inches inside the protective white plastic sheathing. The result of this occurrence is without a doubt why I was having all the odd behaviors. Several power cables had become joined to several grounds. I had been looking for damaged wires specifically in the location where the damage occurred - the left rear tail lights. There was but 1 tiny nick in the insulation of 1 wire - barely perceptible - which I finally found just last week. Evidently, that was shorting to ground & was enough to create heat further upstream, which is where things really went awry.

Here is the car the day I crashed it. I will get some daytime shots post self-repair job. Even though it was totalled, I was fortunate to not have much at all in the way of actual damage. Some part swapping, several hours with a porta-power & various other methods of persuasion & bending, some rattle-can paint (far from perfect but at least it’ll keep rust at bay). I still need to align my door & body panels but it’s good enough for the time being.

Thanks again for having such a helpful site.

[abscate]

It’s amazing how fast a csar will get totaled here, because someone wants $150 an hour for grunt body work. If you ever go to Eastern Europe where money is tight, for $50 a guy with two hammers would make thst look like new in about an hour.

Okay, a bit of hyperbole, but it’s amazing the invention necessity breeds

[- Pete -]

It’s amazing how fast a csar will get totaled here, because someone wants $150 an hour for grunt body work. If you ever go to Eastern Europe where money is tight, for $50 a guy with two hammers would make thst look like new in about an hour.

Okay, a bit of hyperbole, but it’s amazing the invention necessity breeds

All so very true. While I can’t stomach what today’s “mechanics” & body shop guys ask for an hourly rate, I have a much greater sense of appreciation for the process that goes into fixing a car that has multiple points of impact after having a taste of the labor myself. Run-on? I’m past caring

It’s safe to say I won’t be getting into this field, nor will I be putting having experience in this area on my resume. I recall at several points in the journey muttering to myself, ”I’d do P2 PCV jobs any day over this…banjo bolts? Sign me up!”

[scot850]

Fitting bolt on body panels is as far as I go. I realized many years ago I don't have the patience or skill needed for body work. I have done a few small amounts over the years, but necessity was the only reason. That and the inability to find competent body repair people who give a damn.

I wrote recently about my buddies 99 V70 that was totaled in a parking lot. We sourced the parts for under $500 in the correct color, but as he had already contacted the insurance company, they totaled the car. The process to repair the car is simple, but the process to get it inspected is expensive and a pain as they inspect the whole car, not just the damaged parts and you have to repair anything they find. The process costs around $500 CDN alone plus taking time off to get it done. If the insurance companies here gave you the option to fix it yourself, then the car would be still running and driving. Mind you it possibly is as it never appeared at any local junkyards!

Good luck!

Neil.