6.2 Diesel Fuel Pump Question

[1972K20]

I have a 1988 V30 crew cab 6.2 diesel. I'm working through troubleshooting a fuel issue and I discovered that there is an electric fuel pump under the cab on the passenger side mounted to the frame rail. I noticed the wire for this pump goes along the frame rail, up to the passenger fender and is not connected to anything. There's not even a connector on the end of the wire. This truck has been starting and running without issue for over a year without this fuel pump connected. I don't know where the wire from the pump is supposed to go. Does anyone have a wiring diagram for this truck or know where the electric fuel pump is supposed to be wired? Thanks!