08 JK 3.8
I wanted to DIY the Big 7 upgrade but was having trouble sourcing information, YouTube was zero help, so I finally caved and bought the damn kit from JeepCables. I am going to post as much tech data as I can here to help people DIY and save tons of money. I will edit as I get more info.
Video of install:
https://m.youtube.com/watch?v=ua8uHodPlHk


Red

Batt Pos to Starter 56”
Starter side needs 90 degree lug

Alternator to fuse 46”
Fuse to Batt Pos 14”

Batt Pos to TIPM 25.25”
TIPM side needs 90 degree lug



Black

Eng block to batt neg 34”

Eng block to firewall 24”

Batt neg to fender (body) 20”.



Measurements are from center lug to center lug

Stock Harness Lengths

Batt Pos to Starter 51”

Alternator to Batt Pos 61”

Batt Pos to TIPM 22.25”

Black

Eng block to batt neg 53”

Eng block to firewall 22”

Batt neg to fender (body) 19”.


Kit parts (all are available on Amazon individually)


X4 fuses: 150A, 200A, 250A, 300A, 400A

Different amps for different alternator outputs

X1 fuse terminal

X2 Military Battery Terminals

X2 Military Battery Terminal Covers
(I do not recommend, not milspec, cheap rubber)

X2 Lug Covers for Battery Connections
(Also cheap rubber but do the trick)

X2 stickers

X1 product ad/ “instructions” link

 

I DIY’d it on my 08. Bought 0/2 welding cable from Amazon, 0/2 tinned copper lugs and maybe some slightly smaller ones as needed from the hardware store. Crimped them on with a ghetto press using a pitman arm puller. Works great. Considering doing the same with the pcm ground when I get bored