License / Number plate lights not working

[pandas]

Hi guys

Having issues with the MK5 GTI where the license / number plate lights are not working. No dash warning, housing appears to be giving 0.85v only. Have tried a new set of bulbs with no luck, check both door driver and passenger door wring looms which appears to be intact.

Can anyone give me some ideas on how to diagnose this further, eg how does the wiring loom run? I'll be pulling off the bumper this weekend hopefully to put in a set of lights in the interim if I can't get this fixed (had a spare aliexpress set which I have run some cables to a 12v cigarette plug. Dodgy but it'll do).

Thanks

[JustCruisn]

Are you using LED bulbs or normal ?
The car does a system check on startup and if the bulb test fails it will not send power to it until it passes the next start up test.
LED bulbs usually fail the test as the current draw is too low.

[Lucas_R]

As above - if you are indeed using LED bulbs you will will need to buy new ones that are Canbus compatible. And avoid the cheap and nasty ones off ebay - they are junk.

Somewhere like SupaNova or Blingwork will have what you need.

VW Golf Mk5/6/7/7.5 License plate LEDs - Supernova Lighting

Volkswagen Golf MK4/5/6/7 LED T10 Registration Light Bulb

[pandas]

Standard non LED bulbs.
I did have Genuine VW LED ones in them at first which were running perfectly for a number of years, however have switched them out thinking they were faulty. Not the case unfortunately.

[JustCruisn]

Next steps
Check for corrosion in the light fitting.
Fuses
Wiring, try flexing the wiring harness to the back of the car from roof area to top of hatch. Someone posted about broken wires in another thread today.

[pandas]

Light bulb housings are actually new from what I believe as I was involved in a minor rear accident. I also had the repairers replace the short wiring loom to the housing as I had a spare set.

I'll be pulling off the bumper this weekend to do some more tracing, would anyone know how the wiring looms to its power source? From your explanation, it goes up from the trunk ?

[pandas]

Took the bumper off over the weekend, wasnt getting any volts to the 2 pin lead for the bumper loom. Not sure if that proves much as power may have been cutting out the fact that the car was throwing license light error?
I've ran a spare set of tail lights to the 12v boot socket in the meanwhile to get me out of trouble while driving at night. Will try cut apart the upper boot wiring when i get a chance to check for any short. Am I correct to say any short on the right hand side of the vehicle may cause voltage drops to the license plate lamps?
Took the time to also remove and reinstall all fuses, some looked a bit gunky however all appear to be OK - no shorts noticed.

[BorisJ]

Hi, I have replaced the blown light bulbs but that didn't fix the problem. I tested the plug ends but couldn't get a reading. I looked for the fuse for the number plate lights but couldn't find it in the manual. I checked all the fuses on the right side of the steering and under the bonnet but all fuses seem OK. Can anyone tell me is there another fuse location or what else may be the problem why I'm not getting a reading at the plug ends?
Boris