1983 Nissan 720 PU. Fuel Pump doesn't run at start. Been intermittent, I replaced pump but still having problem. Not getting power to pump. I traced cabling from pump to plug under passenger seat, but no power. I ended up running a wire from the low side of the fuse block directly to the pump.

I have an old Chilton book with wiring diagram and it shows nothing between the connector and the fuse block. Any ideas?