Looking to run an 8 AWG wire pair from the battery. Some manufacturers would recommend grounding to the battery, while others recommend the frame (such as where the battery ground strap connects). I guess some of this depends on discharge detection and such. What’s the best practice for the Renegade?
Grounding to the battery should always the first choice. The Renegade has lugs available on the battery terminals just for that. I have seen folks working in the rear of the vehicle and ground to the body without any issues (I am guilty of doing this myself in the past). I have also seen folks wire a light bar on the front of the roof; run the wires down in the roof rack rail to the rear of the vehicle, down the back, under the lift gate to the light (left rear light to be exact), down to the bottom pinch weld, up to the front of the vehicle into the engine compartment just to use the battery ground. It made for a very clean install, the light was properly grounded, but it also cost him 50 feet of wire (50 feet because he ran two wires (power and ground).