fozzie bear

Hey there,

I'm using this guide to try to repair my third brake light wiring issue on my 96 C2: http://p-car.com/diy/glass/

I've been procrastinating on this for ages, but state inspection time is coming up, so it's time to bit the bullet and get it done. I've seen some other threads on this repair in general, but would appreciate advice on my specific situation.

I've done some diagnostics to get to this point:

1. The third brake light works on its own, disconnected from the car.
2. I get ~12V at the solder points on the inside of the car
3. I get ~6V at the connectors on the outside of the car - resulting in no brake light illumination. Not 0V, but not enough for things to work right. Anyone else had partial voltage (non-zero) when checking the leads that connect to the TBL on the exterior?

I'm just about to start step 6 of the DIY and have taken a photo of what I see from the outside of the car. (image attached)

I can faintly see the dark brownish looking copper "flat wire" that goes under the seal, and it looks like one of the two sides of the wire has either broken off or lost some of it's nicely soldered connection, resulting in the lighter spot you can see in this area from the outside. Is what I'm seeing the common problem that this DIY is designed to fix? Does this look familiar to those of you who've gone through this?

I think I can almost see that weird looking solder point from the inside, right up against the seal. Should I just try a dab of solder on it before digging into the window seal?

Thanks in advance!

Bill Verburg

I had 0v, the expensive fix is new rear glass, the cheap fix is to do what was done on the RS, run 2 wires around the edge of the glass from the connector on the rear shelf.

pirahna

Yep, mine didn't work and it worked fine after new rear glass was installed.

fozzie bear

Thanks for the replies so far. I'm really hoping it doesn't have to come to rear glass replacement, from a cost point of view. Some older posts on this topic looked like people had luck with the DIY I'm attempting. Advice from anyone that's done this particular procedure would be appreciated.

Thanks!

Kika

I made a small hole at the top of the glass and through and pulled new wires through and reconnected the electrical on both ends. It was time consuming and I had to keep going in and out of the car. Once the wires were in place and I tested the connections, I sealed it up with some silicone.

Actually not so much of a hole, but a larger opening where the solder connections are. I bypassed the solder that goes through. I figured if it failed once, it could fail again.

coreseller

I did the same, it took some time and patience and alot of getting in and out of the back seat. Dug at the hole with small screwdrivers to ultimately make the path the drew the wires through.

JB 911

Some good ideas in this thread. Mine could be a bit of a band aid fix for you but thought I'd throw it out there anyway. If you have any inclination to replace your stock bulbs with the leds, they light on less voltage. In this pic I was using a 9v battery to test my progress, but I believe they'll light with as little as 1.5v. Your tested 6v could last for years with leds. It could also fail completely next week.

Kika

I'm 5'8" and it was a PITA, I feel for you tall guys!

Once you have the opening, it is difficult to push wire through, so I used some stiff green wire (not sure what it is called, but it is stiffer than the stranded wire, so it went through the opening a bit easier, once it was through, I wrapped the end of the electrical wire around it, to pull it through.

I think it is the wire that florists use to wrap around flowers to make arrangements and stuff. I have a roll of it in the garage, comes in pretty handy sometimes. You can probably find it at Michaels or Joannes if you have those around, or any yardage store.

pp000830

See below for alternate easy way to rout a new wire around the glass:
https://rennlist.com/forums/993-foru...t=high+mounted

fozzie bear

Great suggestion. I'll have to try this. Sounds like it may remove some of the tedium involved. In order to get the opening in the sealant in the first place, are you actually chipping away the sealant with a tool (i.e. removing pieces of it) to make a hole? Or are you simply trying to "poke" a hole through the sealant and drag the wires through?

Also, are you going at it from both inside and outside trying to get through the sealant?
I am 6' 3" so you can imagine the pain I'm in when sitting in the back seat. Haha.

Also, JB 911, you're right, that could work. I think long term, I might go LEDs in the TBL bar, but do want a long term solution. Who knows why or how long I may be getting ~6V at the outside if I just leave it

pp000830, thanks for the alternate route. I think I may try the tedious way that doesn't require drilling, and if that doesn't work, go with your method.

fozzie bear

So I worked at it for about 2.5 hours today, following the DIY steps as a first try.

I think the issue I'm having is I can get a small screwdriver through to the outside, but as soon as I pull it out, the rubber "collapses" back. I need to get rid of more of the rubber in the way.

Kika, did you scrape off the existing outer solder points to make more room, or just go between them? Thanks!

coreseller

I seem to remember pushing a smaller wire through the hole I "tunneled" with the small screwdrivers. As Kika mentioned I used a small craft type of wire, I either folded it flat over the small screwdriver blade then pushed it through or taped it to the blade to get it through. Once through use it to pull / fish the electrical wires through the hole, then strip the outer casing and solder.

Kika

I used an assortment of sharp metal tools, including small jewelers screwdrivers and drill bits.

I used a piece of baling wire (wonderful stuff!!!) as it is pretty stiff, but pliable into a slight curve as a guide to "connect" inside to outside.

Initially, I tried to preserve one side of the solder, as it was making solid contact (measured with an ohm meter), and my objective was to bypass the other side, but after I thought about it, I felt like, if one side failed, the other side might fail as well, so damn the torpedos, full speed ahead and fix both sides.
I measured both sides with an ohm meter, so I knew one side was toast, thus did not worry about "damaging" it further.

I can't say I follow a process that is repeatable, I just tried to use caution as I didn't want to do something that would crack the entire back window.

just work slowly, and patiently.

Kika

I thought about replacing all of them with LEDs as well, as I had like 5 bulbs out. ultimately I figured it was easier to remove and only solder 5 bulbs, than all , what 23?

fozzie bear

As a followup thanks to those that helped in this thread, and to those in the future who read this as they're attempting this DIY... We did it!

It took a while to get the free time to approach this again, but we finally got the wires through, soldered it up, and things are working again just in time for the state inspection renewal that expires end of October.

A couple lessons learned:
1) Be very patient digging through the rubber seal from the inside. Keep going to widen the gap vertically and horizontally. It's not worth trying to feed the wires through until you've created a gap that you think is big enough. Vertical clearance is important, because the rubber closes up the gap easily whenever your screwdriver or other digging tool is removed. I did end up chipping away the sides of some of the exiting outer solder points to make a nice wide gap.

2) If you're tall, get your wife in the back seat to do some of the digging through the seal. I'm 6' 3" and it was a total PITA.

3) Kika's recommendation of florists wire was absolutely critical to getting the two wires through from the outside to solder up. We passed the florists wire from the inside out (easier than getting it around the bend around the end of the glass), then started wrapping the tips of the two electrical wires together, binding them together. Overlapping the florists wire over itself helped keep it secure as we then pulled the wires back through - one person inside pulling, the other on the outside trying to help guide the wires around the edge of the glass.

Anyway, thanks again for all that posted to help us through this! This is the first time I've seen that third brake light alive!