MK5 Electrical Wiring Help

Can anyone help me with the overhead electrical wiring. I replaced my headliner with a used unit and the wiring from the white ribbon cable does not match up with the factory plug in the roof wiring. The ribbon cable powers the two vanity lights and the rear dome/reading light. There are three wires in the ribbon cable, one is 12+, one is ground, and I assume the third is for the door open/dome light activation.

I do not know the order or diagram of the wires now that the wiring is up in the headliner and not accessible. And the fact the ribbon cable has no colors to associate it to matching colors in the factory plug makes it more difficult. Can anyone give me the colors or pin out for the wiring on the ribbon cable? Any help would be appreciated.

Here is a pic for reference on the ribbon cable.

Sorry, forgot the picture




Sent from my iPhone using Tapatalk Pro

I can try looking it up for you if it's in the Mk5 Bentley book.

What did the used headliner come out of?

The headliner came out of another MK5 Jetta, not sure on the year. I did not have a headliner when I bought the car (so no reference) but recently replaced it with one from a local vw parts dealer. The plugs match up and connect on the ribbon cable in the headliner and the wires in the car, just the wiring is out of order in the plugs and I'm not sure how they should be put in the plug.


Sent from my iPhone using Tapatalk Pro

tleader said:

The headliner came out of another MK5 Jetta, not sure on the year. I did not have a headliner when I bought the car (so no reference) but recently replaced it with one from a local vw parts dealer. The plugs match up and connect on the ribbon cable in the headliner and the wires in the car, just the wiring is out of order in the plugs and I'm not sure how they should be put in the plug.

Click to expand...

Jetta sedan?

Is the plug 5 pin, with 3 wires in it?

Yes, Jetta Sedan(4-door). As for the plugs, the one on the vehicle side has 4 wires in the plug. A 12+, ground, dimmable light wire and a forth that is brown with a purple stripe. Not sure if it's CAN related. The headliner side has 5 slots, but only three are used and these are the three in the ribbon cable.


Sent from my iPhone using Tapatalk Pro

OK, are the 4 wires on the car like this?

Grey
Brown
Brown/Violet
Red/Blue

And the 3 wires in the headliner:

Brown
Brown/Violet
Red/Blue

Yes, car side is correct colors. The headliner side I have no idea because they are all the same color(white ribbon cable) so that's where I'm not sure what wires go to the ribbon cable. Is there a pin out that shows PIN numbers related to the plug and ribbon cable? That might be the only way to figure out the correct wiring connection. Hope that makes sense, but with the headliner installed, tracing the ribbon cable has become almost impossible unless I probe the wires.


Sent from my iPhone using Tapatalk Pro

If I'm understanding the Bentley correctly, the headliner plug *should* be a 5-pin connector and go like this:

Pin #1 Unused
Pin #2 Ground (Brown wire)
Pin #3 Wire from main dome light (Brown wire with violet stripe)
Pin #4 12vdc (Red/Blue wire)
Pin #5 Unused

Does that make sense looking at the plug? Are the outside pins empty?

The 4th wire on the car side (Grey, I assume) is the dimmer? Looks like the earlier models...had 4 wires and ran the dimmer wire to the reading lights. After July 2006, there were only 3 wires.

Does that make sense? Is your car an early 06 Model?

My car was built in 09/2006, so not really an early model. As for the plug in the headliner, it's an 8-pin plug with only three from the ribbon cable being used. The three in the plug match up to the 2, 4 and 6 numbers on the OEM plug. Everything else is unused in the 8-pin OEM plug.




Sent from my iPhone using Tapatalk Pro

Ahhh, OK...just hang on then and ignore what I posted above.

tleader said:

My car was built in 09/2006, so not really an early model. As for the plug in the headliner, it's an 8-pin plug with only three from the ribbon cable being used. The three in the plug match up to the 2, 4 and 6 numbers on the OEM plug. Everything else is unused in the 8-pin OEM plug.

Click to expand...

OK, according to the manual, all cars built from 06/2006 only show 3 wires in that 8 pin connector, so I'm not sure why yours has 4. In any case, according to the book, pin #2 is 12v+, pin #4 is the brown wire with violet stripe, and pin #6 is ground.

I can give no guarantees...I'm just reading what's in the book (to kill a little time and avoid something else I'm supposed to be doing...lol).

That's extremely helpful, I appreciate all the research and help. I'll try that out when I get a chance and let you know. Thanks again for the help.


Sent from my iPhone using Tapatalk Pro

Btw, mine does only have 3 pins, it's the vehicle side plug that has the 4th (grey wire).


Sent from my iPhone using Tapatalk Pro

tleader said:

Btw, mine does only have 3 pins, it's the vehicle side plug that has the 4th (grey wire).

Click to expand...

Yeah, it looks like the earlier models had the 4th wire on the car side, and 4 wires in the headliner as well.

Is your grey wire in pin #3 on the car side plug?

VW likely made some rolling changes that don't fit the dates in the book 100%. Just guessing.

Worked like a charm. I had the 12+ and ground reversed originally and it was giving some bleed over to the lights. Once I put the wires in the order you provided, all works perfect. I almost had it right, but close doesn't count. Thanks again for all the help.


Sent from my iPhone using Tapatalk Pro

Happy to have helped.