Need to run some wires through the firewall

[Sloanie]

Need to run some wires through the firewall. What's the best way to do it? I want the wires to end up at the fuse box under the glove compartment

[petemac110]

If you pull some of the carpet back up near where it meets the glovebox, there's a rubber grommet which can be pierced to accommodate wiring. This is how the OBD2 wire for a JB4 is typically routed.

It's a bugger to get to though, and you will ideally need to create a small slit in the grommet to pass the wiring through. A metal coathanger or similar stiff wire is useful to help draw/push the wire through the hole.

The wiring will pop out behind the battery. It can be fiddly to reach - two people (one wiggling from inside the cabin and one waiting with a torch from the engine bay side) makes the job easier.

[petemac110]

Even better... a walk-through with pics! This applies to the Passat too.

Running Cables Through The Firewall – Volkswagen MK7 Golf – AutoInstruct

[Sloanie]

Excellent. Thank you very much petemac110.

[Sloanie]

Just to note on my rline Passat, which has the battery in the boot, I found it impossible to add sealant on the engine side of the firewall as it is very hard to get you hand in where the cable comes through.