Gentlemen,
I am working on an ERR upgrade to this conventional unit. There are two existing wires that run to the each of the trucks. A blk/wht and a solid blk. I assume one is coupler and one is roller pickup. Unfortunately, I can only see the wires running to a harness that is plugged into the truck. I can get no indication as to which wire is pickup roller and which is coupler. Any idea which is which?
Thanks
Troy