1999 Ford F-150 fuel pump

Red wire should have power
if no power check for a short between wire and fuse

With key on check for power
if no power at red wire
check the wiring harness by the wiper motor

OK lets try this
fuse #18 should have power if so and you don't have power on the red wire
you have a short between fuse and the relay

use a test light turn key on check fuse # 18
does it have power if so
check red wire you have to trace it to find the short

or run a new fused temp wire