Thread: Firewall alternative for running cable.

If you get a torch and have a very hard look at the bottom firewall on the driver's , close to the inner guard, there is a small grommet.


Note the location of the grommet and then go into the driver's foot well, up behind the accelerator peddle.


You need to pull the kick panel out and then pull the carpet down.


Then you need to push your hand up under the insulation, about 15cm and you can feel the grommet.


Pop the grommet out with your finger then get a length of straightened coat hanger wire and push it through the hole from the engine bay side.


The hole is big enough to fit 2 x 6B&S cables through it.

Originally Posted by DiscoJeffster

I'm sorry, but why? A 10mm hole is not exactly going to affect the structural integrity? A hole directly next to the existing hole, which has been rust treated and uses a grommet isn't going to harm anything.

If drilling another hole i would go 20 or 22mm,then you will be able to fit a grommet and still have room for extra cables.
With a 10mm hole,after fitting a grommet,there won't be much room left for cables.

Or follow Tims advice and see how you go.

Whether it's right or wrong to drill a firewall, you only have a problem if you get caught.
An easy way to get around this is to make it look factory.
Deutsch panel mount connectors, FTW.

Originally Posted by Russrobe

Pretty sure you can't go just drilling holes through the firewall lol.

It'd be a trick getting a drill up/down to the fire wall, that's for sure

Originally Posted by LandyAndy

Another hole should be OK Russ,make sure its where you wont drill into anything.Make it big enough for futher use and make sure you get the correct size grommet.I would paint the exposed steel too.
Andrew

I spose if one could be bothered you could enlarge the existing hole... perhaps that's good advice for people starting out that think they might want to run all those wires eventually?

My D3 has 2 holes in the firewall , if you look at the brake booster from the front , at about the 1 oclock position but say 50mm to the right is a large hole which I run about 4 cable thru for the UHF, battery monitor etc , and at about 7 oclock but down just above the start of the wheel arch is a smaller hole which easily fits the duel battery cables running to the back. Drivesafe's how to with the dual battery setup tells you to use this hole and from memory it comes out behind the drivers kick panel near the accel pedal.


Cheers Ean

You might think you are at capacity, but i can guarantee you can do more. I have 2 aerial leads (UHF and LTE), traxide, and at least 3 other wires for switches etc. To make it easier, you can remove the grommet away from the firewall and enlarge the hole in the grommet which may help.

Originally Posted by drivesafe

If you get a torch and have a very hard look at the bottom firewall on the driver's , close to the inner guard, there is a small grommet.


Note the location of the grommet and then go into the driver's foot well, up behind the accelerator peddle.


You need to pull the kick panel out and then pull the carpet down.


Then you need to push your hand up under the insulation, about 15cm and you can feel the grommet.


Pop the grommet out with your finger then get a length of straightened coat hanger wire and push it through the hole from the engine bay side.


The hole is big enough to fit 2 x 6B&S cables through it.

Ah nice! Between these two hole I think you could run everything required. I'll go try find this, so far I've squeezed all cables through the other grommet, further up an above the brake pedal and have split the grommet trying to feed more cable. Can't really file or bore out the hole now as it would be hours of work removing enough cable to do so.

As mentioned it would be a great idea to enlarge the hole another few mm before running any cable.