R.H. tail light gone?

[ksanturion10]

Dear fellow and knowleageable people,
recently found out, that my R.H. tail side light doesn't works. Before the winter I think it was still glowing. I've checked the following:
1. The Light bulb is OK, actualy there is new one as my fine engineering hands managed to destroy it ;
2. Everything is sound regarding the bulb/holders and pin/cable-connectors connections;
3. The common mass (ground) from the 3 pin yellow connector is OK;
4. The one green cable from the 2 pin brown connector gives 0,1-0,3 V with the mass, the other green gives slightly under battery voltage (~ 12 V). Between them I read around 5-6 V, so it seems the first one is shorting somewhere. The L.H. rear bodyshell light is there, so I guess the problem lies somewhere inside the right flexible door cable grommet?

If someone had already came across similar problem, maybe could point me in the right direction of the possible shorting location?

BR
Martin

[admiral51]

Do not trust a new bulb because it is new.
Use a known working bulb and see if it works in the R.H. side and the L.H.
You can also remove all other bulbs and with lights on put each one back to see if there is one that causes the issue

[xantia_v6]

Note that each tail lamp has a separate fuse, probably F4 and F9 in the fuse box under the steering wheel.

[ksanturion10]

Actually, under R.H. tail side light I meant the one, that is onto the boot door not the R.H. bodyshell one.
Yes, looking at the wiring diagram F4 and F9 into the passengers compartment are the ones supplying the side lights. But, because only one of the tail lights, except the plate lights, which are both blown, doesn't work, I suspect short somewhere either into the L.H. side bodyshell light assembly or after it, as I guess the wires to the R.H. side tail boot light go from there and up through the grommet.

@admiral51 - good point, but the measurements are trying to tell a different story . Actually, the defective light bulb idea could be true for some of the other ones, so this "brute force" method you are suggesting might be useful in the end. First will try to find out, why the one green cable from the 2 pin brown connector, supplying the R.H. and L.H (trought the 4 pin blue connector) side tail boot lights, shows such a low voltage (0,1 V).

P.S.: I think there is a design mistake into the inner side of the boot, as I can't see a way to unclip the L.H. plate light bulb holder without breaking it?

[xantia_v6]

In that case, it is almost certainly a broken wire in the harness near the hinge where it flexes as the tailgate is opened.

[ksanturion10]

That is going to be tricky . Any suggestions?
Think the only proper way would be new cables, at least at the flexing point...

[admiral51]

That looks like
A. Someone has been there before.
B. Not too bad a job.
I would remove the black tape first to see what has been done that the picture does not show, fingers crossed it is just extra tape to try and stop any water getting in as IMHO those wires look like they have been stripped to make a join not like a simple break in the wiring, 2 of them look the same length but the white one is shorter so that makes me think it has been cut back.
The rubber flexi can be cut and resealed if you can cut it along the seam line which you can see where your left thumb holds the flexi .
Assuming that the break in the wires is not under the black tape, which looking again at the picture i think the tape is there to stop any rubbing of the wires onto metal, i would split the rubber flexi maybe 2 -3 inches below where you are holding it.
I would cut all the wires where you have breaks in the photo, solder an extra wire to each with heat shrink cover allowing enough length for each new wire to allow be joined where you have cut into the rubber flexi .
This allows easy access to the wires lower down in the flexi to join them and lets you push the join of the wires back up into the boot recess so less stress on those joins.
Depending on how long you want to keep the car you can also add an extra wire to one of the joins which get pushed back into the boot and cut it off/tape it so you can use it like a pulley to get to the wiring that you cannot see, ie the joins you have made and pushed into a void.
Do not cut the flexi where it seals into the boot, you will never get it to seal as it should.
Windscreen sealant is flexible and that is what i have used to help seal older rubber flexi seals and it can be used on the flexi where you would need to cut/open up as it has some give in it .

Colin

[ksanturion10]

A. Someone has been there before.

-> Definitely yes, the inner door plastic cover is missing ("the membrane") and the wiper motor was just opened, closed and placed back - I guess all that mess is because they were trying to solve the non working wiper motor.

B. Not too bad a job.

-> Not really sure, what you mean, but it will be a struggle .

I would remove the black tape first to see what has been done that the picture does not show, fingers crossed it is just extra tape to try and stop any water getting in as IMHO those wires look like they have been stripped to make a join not like a simple break in the wiring, 2 of them look the same length but the white one is shorter so that makes me think it has been cut back.

Yep, this will be the first stop as there are more such wrappings also inside the door. I guess will have to check them all. I think the tape is just to hold all the wires, they had disturbed, back to the main harness. The breaks are all at the same places, its just that I pulled the grommet towards me and the greens poped a little bit to the front - optical illusion given the camera angle. The opposite strands are in the grommet and missing from the picture. There is one thicker grey cable that has its pvc coating like cutted at two places right, where the flexing happens, so I tend to think that the thinner ones on the picture had broken by themselves. Ofcourse its possible they got some "help" in the end .

Assuming that the break in the wires is not under the black tape, which looking again at the picture i think the tape is there to stop any rubbing of the wires onto metal, i would split the rubber flexi maybe 2 -3 inches below where you are holding it.

Possible yes, but actually, despite its weight, the door is plastic from the inside .

I would cut all the wires where you have breaks in the photo, solder an extra wire to each with heat shrink cover allowing enough length for each new wire to allow be joined where you have cut into the rubber flexi .
This allows easy access to the wires lower down in the flexi to join them and lets you push the join of the wires back up into the boot recess so less stress on those joins.
Depending on how long you want to keep the car you can also add an extra wire to one of the joins which get pushed back into the boot and cut it off/tape it so you can use it like a pulley to get to the wiring that you cannot see, ie the joins you have made and pushed into a void.
Do not cut the flexi where it seals into the boot, you will never get it to seal as it should.

I think, that the hole in the door for the rubber grommet is just big enough so the 3-pin yellow connector could pass, and so will try to pull the whole harness back from the door! In that way I will check all wires for signs of "over flexing" . Think to put new cables and crimp them at the most easiest places - the iside of the door and somewhere at L.H. body shell light level from the inspection holes . That pulley thingy, you suggest, will get into buisness definitely, when I'm going to pass the new wires.

Windscreen sealant is flexible and that is what i have used to help seal older rubber flexi seals and it can be used on the flexi where you would need to cut/open up as it has some give in it .

Yup, have one just expired not opened tube, will need it for sure around the wiper motor assembly hole, where I saw, that the door screen rubber seal had open up (probably letting water inside ), because of too tightening of the wiper motor top seal nut!

Well thanks Colin, really appreaciate your suggestions and ideas!
So, now with all that info in mind, will have to go down and actually do it

[admiral51]

Do not forget to take photos