[Resolved] LHS trailer indicator not working

[Billbobaggins]

Hi all, have searched thoroughly but cannot find the answer so hopefully someone knows

My left hand side trailer indicator does not work. I have a 2019 Caravelle with a factory fitted towbar and 13 pin socket.
I have tested the trailer and there is continuity on the indicator, I have checked the 20a fuses in SH5 & 6 and they are good.
Have tested the connections in the trailer socket so assume it is before that.
I do not know where the loom connects so I cannot test for a break in the cable or bust connection. Any help would be great.

David

 

[Ads_Essex]

There are a few threads on the near side indicator fault - one mentions an oxidised fuse (along with its location)

Just in case anyone has a similar issue with a right connections loom there were two 15amp fuses on the loom near the battery which had oxidised one of which caused the poor connection. Interestingly both fuses weren’t mentioned in the installation guide I had so was more luck than fault finding.

This doesn’t show a resolution, but on reading it I wonder if the LED itself is an issue, it perhaps requiring a resistor -

I have VW trailer wiring on towbar and led lights on boat trailer. The warning symbol comes on with "check left tail light".
I know this is triggered by led lights and vw sell an adapter to rectify , but it is quite expensive.
As all my lights are working correctly on van and trailer when connected, will there be any problems if I just ignore the warning signal ?
Thanks Cheers.

 

[DaveD]

Hi all, have searched thoroughly but cannot find the answer so hopefully someone knows

My left hand side trailer indicator does not work. I have a 2019 Caravelle with a factory fitted towbar and 13 pin socket.
I have tested the trailer and there is continuity on the indicator, I have checked the 20a fuses in SH5 & 6 and they are good.
Have tested the connections in the trailer socket so assume it is before that.
I do not know where the loom connects so I cannot test for a break in the cable or bust connection. Any help would be great.

David

To be clear, in the 13 pin socket on the van, is the 7 pin live when the indicator is activated?


I assume that you've tested the earth on the bulb holder in the trailer.

 

[Salty Spuds]

Before you start taking things apart & getting the meter out, plug the trailer into a different car & prove the trailer. Then, if available, plug a known good trailer into the van & prove the van.

 

[Billbobaggins]

To be clear, in the 13 pin socket on the van, is the 7 pin live when the indicator is activated?

I assume that you've tested the earth on the bulb holder in the trailer.

Have tested the Earth on the trailer and it's good. There is no voltage on any of the connectors and have no plug in tester but the running I lights are working

Before you start taking things apart & getting the meter out, plug the trailer into a different car & prove the trailer. Then, if available, plug a known good trailer into the van & prove the van.

Have just done that and indicator works on trailer

 

[DaveD]

To be clear, in the 13 pin socket on the van, is the 7 pin live when the indicator is activated?
View attachment 250056

I assume that you've tested the earth on the bulb holder in the trailer.

Apologies, I meant number 1.

 

[revdecal]

Hi all, have searched thoroughly but cannot find the answer so hopefully someone knows

My left hand side trailer indicator does not work. I have a 2019 Caravelle with a factory fitted towbar and 13 pin socket.
I have tested the trailer and there is continuity on the indicator, I have checked the 20a fuses in SH5 & 6 and they are good.
Have tested the connections in the trailer socket so assume it is before that.
I do not know where the loom connects so I cannot test for a break in the cable or bust connection. Any help would be great.

David

Can also be the earth at the back of the rear light cluster. I have a Debon trailer and struggled with the same thing. The back of the rubber plug on the earth was hanging out. Plugged it back in and its worked ever since.

 

[Salty Spuds]

To be clear, in the 13 pin socket on the van, is the 7 pin live when the indicator is activated?

Yes—no—yes—no……

 

[Billbobaggins]

Apologies, I meant number 1.

No-No-No-No......

 

[Billbobaggins]

Can also be the earth at the back of the rear light cluster. I have a Debon trailer and struggled with the same thing. The back of the rubber plug on the earth was hanging out. Plugged it back in and its worked ever since.

On the van or the trailer?

 

[revdecal]

On the van or the trailer?

Trailer

 

[Billbobaggins]

I saw mention on another thread about a green connector under the seat after investigation it is indeed the wiring to the 13 pin socket. There is no continuity on pin 1 (black with white strips wire)! I rigged up a bypass and the LHS indicator works but the dashboard flasher is now rapid for both indicators and the faulty light is also illuminated?

1 step forward 2 steps back

 

[roadtripper]

On the full 13 pin module there are 4 fuses not 2 - this is for a 6.1 but worth a cross check?

https://www.t6forum.com/threads/which-towing-fuse-does-what.44984/

Just checked the 6 wiring diagram and it's quite different so likely a red herring

 

[roadtripper]

Has this trailer worked in the past?

Does it have incandescent or LED lighting?

Do you have another trailer or light board that does work to rule out a compatibly issue?

 

[Billbobaggins]

Has this trailer worked in the past?

Does it have incandescent or LED lighting?

Do you have another trailer or light board that does work to rule out a compatibly issue?

The trailer works perfectly with my car and it has incandescent lights and I've tried a friends trailer with the same result

 

[roadtripper]

Have you checked in the trailer socket itself?

I'm wondering if water has got in and is causing weirdness.

 

[Billbobaggins]

Have you checked in the trailer socket itself?

I'm wondering if water has got in and is causing weirdness.

Yes all looks good no corrosion and I've tested continuity on all the wires

 

[Billbobaggins]

Update

After a bit of figuring stuff out, found a green socket/plug under the drivers seat and tested continuity on the middle pin and the black white wire which corresponds to the LH indicator (no continuity). Then I found another connector in the D pillar and checked again. Found a break in continuity between this and the socket. Rewired this and everything is now working!

 

[DaveD]

Update

After a bit of figuring stuff out, found a green socket/plug under the drivers seat and tested continuity on the middle pin and the black white wire which corresponds to the LH indicator (no continuity). Then I found another connector in the D pillar and checked again. Found a break in continuity between this and the socket. Rewired this and everything is now working!

Well done, you've saved yourself a ton of money!