Routing wires from engine bay to cockpit?

**B6 Dude** · 08-17-2008 04:04 PM

The only thing I've found on this is running the wires outside the car (in the wheel well) or through the ECU box. Both of which have it's unappealing points.

I have a spare cover on the firewall (next to the heater hoses) that seem like they would route to the cockpit. I've punched through the insulation (arrow in first pic), but I've not been able to snake the wires through -- they go in about a foot, but do not come out anywhere visible under the dash. The stuff behind the dash (AC evap/blower, etc) is very close to the firewall, so I'm starting to doubt if there really is access through here.

Anyone gone this route before or have any thoughts on this?

Cheers,
-Neil.

**dougyfresh** · 08-17-2008 04:09 PM

I have three bundles of wires going through the ECU box. Can you see them in this pic? (I bet NO)

I snuck them in through the rubber boot that carries the engine harness (on the underside).

I have not tried the alternative location you suggested.

**B6 Dude** · 08-17-2008 04:14 PM

I was really trying to avoid the ECU box, so I'm still trying this route... waiting for a friend's help so I can try wiggling some stiff wire from the cockpit side and seeing if it can be accessess from the engine bay side. I need to route a harness with about a dozen wires through there.

**dougyfresh** · 08-17-2008 04:21 PM

Gotcha. Let us know how it goes.

**B6 Dude** · 08-17-2008 06:20 PM

Will do, but looks like it won't happen today. Everyone's hunkering down for a hurricane.

**dirtybrd** · 08-17-2008 06:30 PM

There are a few nipples on the rubber boot for the ECU harness, you can cut one off and run the wires thru there.

**B6 Dude** · 08-17-2008 07:19 PM

Got it!

With some experimentation, I found the correct angle to push a sacrificial plastic hanger from the engine-bay side, and was able to see it from the passenger-side footwell. This is indeed a very direct and short route. I ran my wiring harness and a length of boost hose, but stopped here for now (rain). Thanks for the help -- now I can finish the rest of the "mod" which this is for. ( Yes, I'll post more on that later.

)

Cheers,
-Neil.

**Capt. Obvious** · 08-17-2008 08:22 PM

Good work. That's where my power cable for my air compressor comes through. It's a pain in the ass, but it's doable. Took me about 20 minutes to get the coathanger through.

**B6 Dude** · 08-17-2008 09:13 PM

I wouldn't really call it difficult or time-consuming with the right tools. Because of the not-too-straight path, metal wire would get caught on things or bent while being pushed through. The plastic hanger made it so much easier -- like 2 minutes to find the correct angle.

**AudiA4_20T** · 08-17-2008 09:47 PM

cool man, thanks for the pic

**diagnosticator** · 08-18-2008 06:38 AM

On the firewall, down low, there is a large rubber grommet, with plugged pass through holes provided. The pass through is low enough that the wires pass below the plenum, and don't go through the plenum space.

**B6 Dude** · 08-18-2008 09:35 PM

Yeah, while routing the boost hose later last night, I saw a couple plugs on the firewall between the battery and the cabin air filter, but I couldn't see the outlet in the cockput area. By then it was too late anyway :)

**Stockton** · 08-18-2008 09:53 PM

I ran the power for my amp in through wear the cabin filter is and it comes out behind the AC stuff on the passanger side behind the glove box. I didn't go through actually filter part, there was a rubber plug that come out. I took the glove box while I did it but it was pretty easy and everything is hidden.

It's a good spot cause you can then run the wires up under the dash to either side easily while keeping everything hidden and neat with zip ties.