Window switches, mirror adjuster and lock unlock buttons not lighting up. Driver mirror not folding and adjusting

[Octavian Birda]

Hi all.
So a really weird thing started happening. At first the backlight on the mentioned buttons started flickering when the mirror heating was turned on, then they wouldn't light up at all. Weirdly the button for the window lock does light up when pressed. Simultaneously the driver mirror wouldn't fold and the adjustment stopped working. The windows work as they should.

I checked the fuses and they all seem ok.
I have no idea what else to check next.
The car is a 2011 Leon 1.4tsi.

 

[tracktoy]

Sorry not a car i know a lot about but have you run a diagnostic scan to see if any errors are being shown.

 

[mty12345]

I'm not that familiar with the mk2, but sounds like it could be a ground issue.

In the Mk1, most things in the doors share a common ground wire, which runs through the rubber 'Accordian' shaped seal/boot, and into the drivers footwell where it goes to an earth point bolted to the body. Likely the mk2 is pretty much the same and I'd suspect a broken wire somewhere in there.

If you remove the window switches and find which wires are ground (there are usually 2 or 3 and normally brown in colour), then find the other end at the earth point in the footwell area. Use a multimeter or better still a small test light to check if you have continuity between those two points. If you don't have one or know how, quite possible that a visual inspection may find it. 99% of times it's where the wires flex as the door opens and closes.

The reason that a test light is best, is that is shows that the wire can pass a proper amount of current, whereas a multimeter can sometimes be misleading because any current passed at all with show as continuity, so you can have a wire that is 99% corroded, but still show as good. Could well be the case here as things like the backlighting and mirror fold/adjust use a lot of current, whereas the actual window switches and lock buttons are very low current.

Hope that rambling makes sense and is some help lol

 

[Octavian Birda]

No errors were found with a basic obd dongle and phone app scan.

Will update when I get the chance to take it apart.

I'm not that familiar with the mk2, but sounds like it could be a ground issue.

Coincidentally the driver door doesn't lock or unlock when I use the keyfob, and the little red light on the door stays on for a few seconds after I press the lock button. The other doors lock just fine.

All these issues began roughly at the same time.

 

[mty12345]

Coincidentally the driver door doesn't lock or unlock when I use the keyfob, and the little red light on the door stays on for a few seconds after I press the lock button. The other doors lock just fine.

Definitely supports the broken/corroded wire theory.

 

[Octavian Birda]

There seems to be some sort of heat damage besides the corrosion. Shouldn't there be a pin in the circled spot?

 

[mty12345]

I'm not sure mate to be honest, quite possible. Heat damage can happen when the connection is so corroded that the resistance of the pin goes very high. High resistance = Lots of heat.

I would try cleaning it with a toothbrush and either isopropyl alcohol (IPA) or better still a good contact cleaner, plug it back in and see if you get lucky. If not then you will have to replace the connector, or do a 'cowboy repair' and bypass the connector.

 

[Octavian Birda]

I did a clean up with contact cleaner but no results. I'm pretty sure there should be a pin there since there's a corresponding metal connector on the female side.
This is beyond my skills and tools so I'll take it to someone in the near future. Will update with the outcome.

 

[mty12345]

I did a clean up with contact cleaner but no results. I'm pretty sure there should be a pin there since there's a corresponding metal connector on the female side.
This is beyond my skills and tools so I'll take it to someone in the near future. Will update with the outcome.

Yeah probably best mate. Should be easy enough for a auto electrician.