DRL issue

[Droneshadow]

I mentioned this in another post but I’m tearing my hair out with it now, so I’ll ask directly in case anyone can shed any more light on it. (Pardon the pun)
2019 T6
Changed the headlights to the factory H7 ones, and fitted Twenty20 DRLs
All worked fine fine for a couple of weeks, then bulb out warning light appeared and both DRLs were not working. Managed to get the drivers side out, old style bulb holder but excellent condition, LED working fine. Carista says left DRL short circuit to ground, right DRL short circuit to ground.
Checked the fuses in the panel to the left of the gearstick, all ok,
My questions are, am I looking at the correct fuse box? From what I have read on here it should be the C fuses, but not sure where they are located.
And, would a blown fuse give a short circuit to ground reading? Does fact that they are both out suggest a fuse?
They worked fine initially, and the drivers side bulb and holder are ok on testing yet not working, when fitted. Seems odd, I’m thinking if I take out the passenger side I’ll find the same.
Any thoughts would be much appreciated, thanks, Chris.

 

[roadtripper]

Is the error something like "Open or Short to Ground"?

Generally that means there is no rational voltage being detected in that circuit so either a fuse or wiring fault.

 

[Droneshadow]

Is the error something like "Open or Short to Ground"?

Generally that means there is no rational voltage being detected in that circuit so either a fuse or wiring fault.

Hi, it’s short circuit to ground, I’m not sure where the relevant fuse is, read on here there are several lighting related fuses with C numbers, but I can’t find where they are.

 

[roadtripper]

The H7 current flow diagram is here:

https://www.t6forum.com/threads/h7-headlight-wiring-diagram.10508/

Check the fuses mentioned on there.

 

[Droneshadow]

Thanks for that, I can see L174 and 175 are the DRLs, but I’m no electrician and can’t figure where the fuses are from there?

 

[roadtripper]

The problem with the current flow diagrams is a lot of stuff goes through the "onboard supply control unit" and it's not clear what fuse feeding that unit matches which output.

However all the fuses on those diagrams are to do with lighting so if you look in the key they are labelled by fusebox - so SC09 for instance is in fusebox SC

If you check them all then at least you are sure. The diagram also shows the wire colours if you need to trace the wire to look for damage or bad connection.