Tail light help

[848phantom]

Okay so background is I got a 2008
A4 saloon.
I knew it had a few different faults I could fix so got it down to a real good price.
The tail light clusters were rotten so removed them , sealed them up, added two new clusters and two new plugs with new pins. But the problem I'm having now is the inner tail light on the left hand side . It's not lighting but when I put on the fog light it glows dim. This car is the pre facelift so four pin plug and shared earth so am I right in thinking it can't be the earth or all the inner lights would be out?
So could it be the supply wire needing replaced for the tail/fog bulb or would it be the comfort controller ?
Anyone have this happen them before?
And funny enough I seen another b8 sline and the same light was out

Thanks

 

[NHN]

If the connector & supply wires are the same for each side, (check wiring schematic before doing as could have different wire positions on other side) then test on working side to prove the light is good or not.

 

[848phantom]

If the connector & supply wires are the same for each side, (check wiring schematic before doing as could have different wire positions on other side) then test on working side to prove the light is good or not.

Yeah the pins are back to front on the other side, auto spark has told me usually is the supply wire causes an issue an can run a heavier gauge wire from the CCM to the light

 

[NHN]

Doesn't need a heavier wire generally, they're already overcompensated for, its either damaged or lense fault.

Just fit a temp wire to test from the module, easiest way to test.

 

[848phantom]

Doesn't need a heavier wire generally, they're already overcompensated for, its either damaged or lense fault.

Just fit a temp wire to test from the module, easiest way to test.

Slow getting back as was away on a driving hol lol.I think his idea is the wire is breaking somewhere, hanging by a stand if you know what I mean.
If it isn't the wire the cluster is brand new so only other thing I guess would be a faulty CCM