it tock a bit of searching but i found this thread...
http://www.ridgelineownersclub.com/forums/showthread.php?t=33946

 

all I can find is yellow/black - lt. green/red +, for a 2010. as unchanged the truck has been over the years it's probably the same. if you can find wires that color right next to each other in a harness that's probably it.

 

Behind the radio?

A harness is used for the factory sub, it is connected on the back of the factory head unit. If the HU was replaced that harness should be laying around in the dash behind the HU and you will see the yellow, black, and green/red wires with the harness.

 

I'm trying to hook up my Amp from my supwoor and I need to know how to do it right like all Color coated wiring down a diagram on a two thousand eighteen honda Ridgeline

 

A: don't revive threads just to hijack them. Or revive them at all if possible. B: post in the relevant section for gen2 Ridgelines. C: welcome to the club.