I'd also look at the connection type there may be a third wire for chasse ground protection already if not just don't use the third wire as long as the individual wires are of sufficient size for the load. Just cut it back out of the way.
Making DC power cable with 3 wires
Hi,
I have a piece of power cable that I want to use to upgrade my DC cable. That power cable has 3 wires in it, while a DC cable only need two. What would you do with the third wire? Would you just ignore it, or connect one terminal with two wires and one terminal with one?
thanks.