Under the driver’s side door trim.
And through the firewall grommet I used for the grille light bar install using the same copper pull wire technique.
Once in the engine bay, I pulled enough wiring through plus 12” to reach the battery. I then cut and installed the same Flexo wrap used in the other light bar install over the wire to protect it in the engine bay. Shrink wrap on both sides, and a water tight battery connector on the end.
I then pulled the slack 12” back through the firewall so the Flexo extended from the driver footwell into the engine bay. I tucked all wires away, reinstalled all paneling and wrapped up that portion of the install. I left the wire disconnected from the battery for obvious reasons.
At the back of the hatch, I started by installing the switch on the passenger side hand hold using a step drill to create the hole for the round weather resistant switch.
I then took the wiring harness through both holes, attached the hot wire from the battery to the positive wire on the harness, and routed the negative wire from the harness through a factory grommet and onto a factory hatch bolt.
Hooked up the switch wires as it came, and reinstalled the hand hold on the passenger side, with the switch.
Pulled the slack out of the wiring harness and used zip ties to clean everything up.
[Daytime!]
I then used the step drill to hone out the mounting hole for the light, and the hole for the light wire to come inside the hatch.
Because I wasn’t going to be able to secure the bolt inside the hand hold due to the light blocking it once in place, I used a rubber washer to allow the bolt to have enough traction to allow me to tighten without causing the bolt to simply spin. For this reason, I also opt’d away from the supplied nylon lock nut and favored a jam nut set up because it would put less rotational force on the bolt (eliminating spin and allowing it to tighten). To get the light wire through the hole I dirlled, I removed the provided deutsch connector, fed through and reinstalled it.
I zip tied all bound wires to a support inside the hatch to eliminate any rattling or clatter from the hatch.
Plugged it in, and reinstalled the hand hold with the light into the hatch!
It does stick out of the hand hold because of the mounting bracket, but it clears the bumper when the hatch is shut, and that was all I needed!