Rear Chassis Wiring Question

[Mark Eaton]

I am currently mocking up the wiring, brake lines, fuel lines, etc of the rear end MK4. I need to add several power sources (trunk light, back up light, subwoofers, possibly powered speakers, extra brake light). I am interested in tips or advice on how to run the wires. Should I run them through the Rear Chassis wiring harness? Run them separate in my own harness using that protective tubing stuff? Or just zip tie them back there somehow?

[Jeff Kleiner]

While adding the 4 or 5 extra wires you propose into the existing split loom going to the rear it's probably not all going to fit unless you unloom it and put it all in a larger size. IMO the easiest/cleanest alternative would be to make up your own branch with your wires in a separate length of split loom.

Jeff

[CraigS]

I have no actual experience because I am not into sound systems but on cars I have seen them in, they run some really large wire to power speakers and woofers. Is your battery going to be in the rear or front? The wires for lights could maybe be added to the existing harness but I doubt the speaker wires will fit. I think you will find it easier to make up your own separate harness even if you wire tie it right along w/ the existing harness.

[Straversi]

You are a better planner than I am. I ended up running a separate split loom tubing with wires for trunk light, back up light, seat heaters etc. I of course, did it after the rear aluminum was installed. Much easier to do it early. There is no reason to try to stuff it in the existing loom IMO. Label both ends of the wires.
-Steve

[Papa]

I used braided sleeve everywhere I ran my own wires. It looks a lot better than the plastic split loom in my opinion.

Dave

[GoDadGo]

Whatever you do, the job is a lot easier if you install the rear wiring BEFORE you put the trunk floor down.

[Railroad]

I added 2 wires, one for backup and one for trunk lighting, inside the loom of the harness. Using 16 gauge wire, I had no issues with getting them in the loom. I plan on using LED, so wire size should be good.
Still in the build stage.

[Dave Howard]

I installed the guts of my sound system deck in the trunk along with an amp and the components for satellite radio. The face plate for the deck was installed in a console and CAD5 cables soldered to the tabs on the face plate and the deck. All the wiring was put in separate loom. Lots of work for.....NOTHING. Its a great sound system that you cant hear properly at any speed. To hear the music you need to crank the volume. Then you become "one of those guys" that we all shake our heads at. If you want tunes while you drive, my recommendation is ear bugs and your smartphone.
In hindsight, I wish I had the additional room in the trunk.

[Mark Eaton]

I installed the guts of my sound system deck in the trunk along with an amp and the components for satellite radio. The face plate for the deck was installed in a console and CAD5 cables soldered to the tabs on the face plate and the deck. All the wiring was put in separate loom. Lots of work for.....NOTHING. Its a great sound system that you cant hear properly at any speed. To hear the music you need to crank the volume. Then you become "one of those guys" that we all shake our heads at. If you want tunes while you drive, my recommendation is ear bugs and your smartphone.
In hindsight, I wish I had the additional room in the trunk.

Ugh, thats frustrating. I was afraid I would hear that from somebody. I've thought about trying to find thin subwoofers for inside the **** pit somewhere and installing tweeters and midrange in the trans tunnel??

[Mark Eaton]

I have no actual experience because I am not into sound systems but on cars I have seen them in, they run some really large wire to power speakers and woofers. Is your battery going to be in the rear or front? The wires for lights could maybe be added to the existing harness but I doubt the speaker wires will fit. I think you will find it easier to make up your own separate harness even if you wire tie it right along w/ the existing harness.


Battery in the back

[Mark Eaton]

I used braided sleeve everywhere I ran my own wires. It looks a lot better than the plastic split loom in my opinion.

Dave


Where did you get the braided sleeve?

[Papa]

Where did you get the braided sleeve?

I get mine from Amazon. I bought several different sizes.

https://www.amazon.com/s/ref=nb_sb_ss_i_2_16?url=search-alias%3Daps&field-keywords=f6+split+braided+sleeving&sprefix=braided+split+sl%2Caps%2C176&crid=21LXVWTCD2MWR

You may also want to pick up one of these for any long runs you are making. They come in different sizes to work with the different size sleeves.

https://www.amazon.com/Wire-Loom-Cable-Insertion-Tool/dp/B005DTKNZU/ref=sr_1_2?ie=UTF8&qid=1517801403&sr=8-2&keywords=split+loom+tool

[CraigS]

Battery in the back
That is good for this. I was thinking that the heavy wires I have seen may be to power the woofer but that the actual signal from the head unit might be small wire. If that is the case maybe a heavy wire add-in harness and the small wires in the FFR loom?

[Mark Eaton]

That is good for this. I was thinking that the heavy wires I have seen may be to power the woofer but that the actual signal from the head unit might be small wire. If that is the case maybe a heavy wire add-in harness and the small wires in the FFR loom?

That definitely makes sense.

[Mark Eaton]

I get mine from Amazon. I bought several different sizes.

https://www.amazon.com/s/ref=nb_sb_ss_i_2_16?url=search-alias%3Daps&field-keywords=f6+split+braided+sleeving&sprefix=braided+split+sl%2Caps%2C176&crid=21LXVWTCD2MWR

You may also want to pick up one of these for any long runs you are making. They come in different sizes to work with the different size sleeves.

https://www.amazon.com/Wire-Loom-Cable-Insertion-Tool/dp/B005DTKNZU/ref=sr_1_2?ie=UTF8&qid=1517801403&sr=8-2&keywords=split+loom+tool

Those are slick. Ordered