2004 Ultimate Signal Wires to Aftermarket Head Unit

[Brooklindevil]

A couple weeks ago I installed an aftermarket head unit in my 04 Ultimate and in the next couple weeks I'll be finishing the full audio system set.

However, I'm a touch unsure about getting signal wires from the back of the unit through the dash and down into trim under the door. Ideally the install would be as clean as possible, but while installing the head unit I felt around a bit and didn't immediately find an elegant route.

I've scoured the Town Car forums and just about every video on YouTube to get an idea of where I should aim for and didn't get much back, so I'm very curious to hear from others that have put systems in their car about what they did for this.

Would also be pretty helpful to hear some options for securing the sub and amp on the trunk shelf. I was liking the sound of hiding some plywood under the carpet but if anyone has a better idea or did it differently I'm all ears.

My first post on the forum. Owned the car since December and absolutely adore it!
Thanks!

 

[Brooklindevil]

In the event somebody in my position when writing stumbles upon this in the future, I'll throw some tips and notes that I would've liked to have beforehand here.

All wires fit between the gauge cluster and steering column well. I ran 2 RCA cables along with a bulky speaker wire bundle. Minimal issues.
The cavity for the head unit is very shallow. Had no hope of seating the unit with RCAs plugged straight into the back. Throwing a line converter in the mix which will also solve the problem of my signal turn-on wires all being dead for some reason.

Trim in the floor is unforgiving, and the firewall grommet is a real time. Wires with fuses already attached should be avoided. Pushing from the engine bay into the cabin is an incredible ordeal.
I grounded to a module that itself is grounded just beside the speakers on the top of the parcel shelf. Had to modify the terminal because the bolt was just a bit too big but it works.

Best way for wiring in the trunk is just to climb in. The lowest cubby is pretty roomy. I'm a big guy and I didn't even have to squeeze in.

Almost all relevant interior trim is held on by plastic clips of varying veracity.

Passenger speaker can be replaced without unplugging anything from the door card. Make sure your wiring adapters are plugged fully in. That lead me on a bit of a chase.


I'll add more if I think of anything else.