Need help with Auto Dimming Mirror

Hey guys,
I bought an auto dimming mirror off AliExpress for my 2016 GTI S w/ lighting package. I'm running into a couple issues.

1) in several pictures of people upgrading their auto-dim mirror, in for example the autobahn trim, there is a grounding lug under the overhead map light. It is welded to the roof, with an acorn nut. I have no such ground stud, but I could always use some electrically conductive silver epoxy and make a lug. Or I could just tap into the ground wire going to the map light (more likely easier).

2) the wiring harness that I have has 4 wires. I can imagine that I need +12V, Ground, and a trigger wire from the reverse light, but I can't imagine what the 4th wire is for.

3) The wiring harness wires are Blue/Black, Yellow/Black, Brown/Red, and Brown.
The Brown terminates after ~9 inches with a ring connector for the ground lug (that I don't have).
The Brown/Black terminates after ~18 inches to a female pin connector (for a round male pin)- it is labelled T6b/2.
The Blue/black runs under cloth tape to the end of the harness, and has nothing at the end of it - labelled T73a/64.
The yellow/Black is also like the Blue/black in length, and terminates with a female connector for a small male spade terminal - labelled SC34.

Can anyone help me figure these out?

I just found this image

From here,

But I don't know if it's correct. It shows BRN going to rotary light switch and this lead is definitely not long enough to reach the rotary light switch.
It shows BLK/YEL going to rotary light switch (and it might reach), but also says fuse? Am I supposed to go to the rotary light switch somehow, or to a fuse??
It shows RED/BRN going to an interior light, but I don't have any open pins to connect it to.
It shows BLU/BLK going to the BCM, but I the wire is just clipped with no connector. Should I just posi-tap or 3M scotchlock to that wire without going into the BCM connector?

https://www.dropbox.com/s/lu5c8uvab6fk56a/HomeLinkMirrorMatrix.pdf?dl=0

Check the part numbers for the S vs the SE/Autobahn mirror, and see if they can lead you to some wiring diagrams or some videos.

You may have a mirror intended for a different model.

The frameless/autodimming homelink that most of us add to the car has a simple harness that plugs into the back of the headlight switch. If you need to splice into wires you might want to check out the MK7 service manuals to see what you can splice into.

Personally, I'd just get the frameless homelink. It looks sharp and is an easy install.

cruzmisl said:

The frameless/autodimming homelink that most of us add to the car has a simple harness that plugs into the back of the headlight switch. If you need to splice into wires you might want to check out the MK7 service manuals to see what you can splice into.

Personally, I'd just get the frameless homelink. It looks sharp and is an easy install.

Click to expand...

That’s a nice suggestion but
1) I already have a mirror and harness
2) I don’t have a garage door that I need the homelink for
3) that mirror is $220, almost twice the cost of the one I bought.

I’d like to look at the MK7 service manuals. Where can I find them?

From another member here: https://www.dropbox.com/sh/f99kqqmv66pryib/AAA5LM_C4H6x4l56StzU9YO9a?dl=0

Quote:
Originally Posted by cruzmisl
The frameless/autodimming homelink that most of us add to the car has a simple harness that plugs into the back of the headlight switch. If you need to splice into wires you might want to check out the MK7 service manuals to see what you can splice into.

Personally, I'd just get the frameless homelink. It looks sharp and is an easy install.



That’s a nice suggestion but
1) I already have a mirror and harness
2) I don’t have a garage door that I need the homelink for
3) that mirror is $220, almost twice the cost of the one I bought.

I’d like to look at the MK7 service manuals. Where can I find them?
__________________
2016 4Dr GTI S 6MT Night Blue Metallic w/ LP (US Spec)


Another suggestion would be to check with people here before buying something that doesn't fit.

The Fed said:

Quote:
Another suggestion would be to check with people here before buying something that doesn't fit.

Click to expand...

Oh it definitely doesn't fit... I'm just asking for making an OEM part fit into the trim level that VW doesn't even supply the option of an auto-dim mirror, without having to resort to third-party harness/adapters, or different mirrors.