Any existing holes that are convenient on a 2012 jku (if it makes any difference it is auto). I felt a big rubber booted access port but I don't want to be cutting into the boot..... Btw the diameter that I need is about 3/8"

 

There is a hole with a flat cover on it on my 2014, but it comes out under the battery in a bear of a location to get at. I was able to fish a wire hanger through it. There's also stuff behind the side panels of the dash that come out under the side cowls. I don't care for that location myself.

 

Thanks! I'll have to look for it again in daylight I need to run my in cab winch controller cable out to the winch

 

There's an easier to get to spot on the driver's side, I THINK where the clutch on the manual would mount. I've used that for a number of things.

 

yeah, I got my brake controller wiring going through there. The way though my winch is placed I don't feel like going round the whole engine bay (plus I think I'd run out of wire )

 

The pass through inside the dash that goes under the side cowl (as mentioned above) is a major PITA. There is a lot of foam in there, and it doesn't easily pass straight through like you'd hope. It runs in to things right as it exits, so immediately has to veer to the side from what I can recall. You can bend the cowl back, uncomfortably so, but it doesn't make it a whole lot easier to access from the outside. I had to pass through air compressor wiring and it was a pain. Your loom might not be too bad, But I'd rather remove the batter and tray and use the lower pass through myself.

 

I thought the cowl pass-through on both driver and passenger side was quite easy on my 07 2 door.

 

I will admit that I was pushing through a pretty thick loom for an ARB dual compressor. I recall being so pissed off and spending more time getting that loom passed through the firewall than I did with the complete rest of the install.

 

The hole on the driver's side on mine was as described, a crap-ton of foam and a PITA, but that's where all my wires go through. The passenger's side had very little foam, but had two very sharp pieces of sheet metal in it from the cowl that made me worry about ground shorting the wires I was sending through.

I have discovered, working on my 2013, that there is not always a lot of consistency from one Jeep to the next on things like that.

 

The passthrough on mine was also filled with a ton of foam and very difficult to get wiring through. It has been the longest part of any install I've had to run wiring on. Once through however it's great and easy to run stuff inside the cab