Yes, it is possible, and that exactly how my Leer dealer wired the lights for my cap. Make sure you splice in a quick disconnect plug so you can take off the cap without having to "unwire" everything.
Pioneer head unit, PAC steering wheel control modual, Hard wired Sirius radio, Hard wired radar detector, Piezo beeper for locking doors, Tinted front side windows, , Mini Maglite holder, D-Cell Maglite holder, Weathertech Digifit Floor Mats
BHLM, T-Rex Eyelids, Air horns, Blacked out badges, Smoked Tails, Black Powder Coated Billet Grill, Hella Black Magic Driving Lights, Color Matched Engine Cover, Lund in channel vent visors, FJ Cruiser alloy wheels, Leer 100XQ shell, OEM bed mat, Black Westin bull bar, 4" black Aires tube steps
Bed lights, Guage cluster lights color change, Bilstein 5100's up front