air and defroster not working.was told wire in frame burnt up were is this wire? on 2004 Nissan Pathfinder

my exhaust pipe broke off ,I was told there is some kind of harness in the frame at this location that burnt up ware is this harness,and how can I get at it?

Asked by for the 2004 Nissan Pathfinder
No wires back there for the hvac system. Start by checking fuses.