Trailer lights gone out

[King John]

My car is fitted with a reversing camera and a Westfalia towing hook. Trying to sort out the side/ stop light on one side of the trailer I must have blown a fuse as none of the lights work now. But which fuse?

 

The three assigned fuse positions do not have fuses. The only indication is that the front parking assister no longer works. Could that have been used? Being linear minded I do not understand why a single fuse should have knocked out all the trailer lights as they have separate circuits and their own fuses (all the lights still work on the Superb estate).

 

Hiding the fuses and providing such a small diagram suggests they do not want plebs to touch them!

Edited 30 March by King John

[Stonekeeper]

Earth wire in the trailer plug?

[King John]

I can't think why it should go while I was fiddling with the light unit but then, equally, I cannot think why a single fuse should knock out all the lights and not effect the car

16 minutes ago, Stonekeeper said:

Earth wire in the trailer plug?

 

[Stonekeeper]

12 minutes ago, King John said:

I can't think why it should go while I was fiddling with the light unit but then, equally, I cannot think why a single fuse should knock out all the lights and not effect the car

 

 

the plug on the trailer wires are subject to movement and the weather, oxidation . a couple of times i have had to re-do the connections in the plug on my caravan for one wire or another for individual lamps, but the earth wires would stop the lot.

[Stonekeeper]

Dashboard fusebox fuse 28,38 and 44 are those the ones missing.

 

 

https://ownersmanuals.blob.core.windows.net/ownersmanuals/en/Superb_3V/11-2015/OwnersManual.pdf

 

 

If it's an aftermarket towbar could there be a relay box in the boot that supplies the power to lamps when activated,, maybe a fuse there?

Edited 30 March by Stonekeeper

[Bap33]

1 hour ago, King John said:

Being linear minded I do not understand why...

There are so complex systems in modern cars that sometimes faults are related to another component that you wouldn't think of...

 

For instance, a typical one is a weak battery, it leads to many errors. The last one I've discovered on a friend's MK3 is inability to set the passenger mirror position upon reverse. Even with gear lever in D position, the passenger was going nuts: moving left when pulling the joystick to the  right, moving up when pulling the joystick down and no move at all when pulling right or up.

 

Thus, IMHO theses advises seem to be a good thing to check:

 

1 hour ago, Stonekeeper said:

Earth wire in the trailer plug?

 

54 minutes ago, Stonekeeper said:

 

the plug on the trailer wires are subject to movement and the weather, oxidation . a couple of times i have had to re-do the connections in the plug on my caravan for one wire or another for individual lamps, but the earth wires would stop the lot.

 

Grounding is common to almost all systems... Maybe a reason why... 🤷‍♂️

Edited 30 March by Bap33

[Stonekeeper]

With ""front parking assister" not working i would also check fuse 32 maybe the feed for the towbar wiring relay (if there is one) was taken from the parking sensors?

 

 

Probably end up having to check all the fuses

Edited 30 March by Stonekeeper

[King John]

On 30/03/2024 at 09:55, Stonekeeper said:

 

 

 

If it's an aftermarket towbar could there be a relay box in the boot that supplies the power to lamps when activated,, maybe a fuse there?

It is a Westfalia tow bar, which I believe is OEM for the Skoda tow bar.

fuse 28,38 and 44 are missing.