WolfWhistle, I think what you are looking at is the front frame rail that the electric and lp gas lines are run thru. Batteries must be on a rack in front of that. Like others, it's hard to say what that brown wire is a ground for without seeing more than what the picture shows. Need to see another picture to the right of the first picture, who knows?
2015 24 FQSL NITRO TH
2015 2500 Silverado Crew Cab Duramax 4X4
2012 HD Street Glide
2008 Honda FSC600 Silver wing