Rear cluster wiring

[Terry82]

Hi lads. How can I identify the rear light wiring? I don’t know anything about canbus systems. I’m looking to wire a hitch. I have all the hitch relay boxed wired up I just need to tap into the cluster loom. I’ve been searching for info here but the only description of color codes doesn’t match my wiring at the cluster.

[LC5F]

Struggling to understand what you are trying to do?
When you say:
Cluster, is this the dash?
Hitch, are you adding a tow hitch?

If I guessed right you really should not be messing with the dash loom, all the signals you need to activate relays are local to the tail lights, you will need a power supply from the fuse board - this needs to be fused and when you tap into cables don’t use scotch locks -there is a specific hell for people who use these

[Terry82]

I’m sorry for not being clear on the original post.
I installed a tow hitch, and also a tow hitch wiring kit, which were supplied together
.
I have a fused 12v supply to the relay box, which came with the tow hitch wiring kit.
And I have the cables from the tow hitch plug, connected into the relay box also.
Now I need connect the gti’s rear lights to the tow hitch relay box.
I don’t know how to identify the cables to the  gti’s rear lights.
I’m worried I might damage the ecu with a multi meter to identify the cables

[LC5F]

No problem -
I would either trace the cable from the lamp holder circuit board
or
invest in a Haynes manual -They seem to have pretty comprehensive wiring diagrams

[Terry82]

Forgot to reply back sooner.
Thanks for the tip. I managed to use the light bulb holder circuit board to identify the cables.
Trailer lights all working now.
Thanks