You have to look closely at that Amazon ad; there are 19 different options you see when you click on the picture thumbs.

Pretty simple to use the waterfall, either unused hole or drill/cut new.

Fuse #23 20A underhood fuse box.

 

Good point
My choice was for the 2 round switch, 13/16", two color illumination
Thank you for the fuse location reference

 

Is there a preferred location for going through the firewall?

 

 

Punch a hole in the grommet with a coat hanger.

 

I plan on doing this mod after the new year. right now I am working on improving my stereo sound.

 

Going to finally get around to installing seat heaters next week. Is fuse #23 a constant power source or is it activated by the ignition? Thanks

 

here is the wiring diagram
hseat.pdf

 

Cool thanks

 

Got mine installed over the weekend. Here is the kit I used
https://www.ebay.com/itm/4X-Car-Seat...53.m2749.l2649