The drawing below is from my '95 F53 shop manual, but I believe it's the same layout as your '97 chassis. The horn relay is the same part as the fuel pump relay, so assuming your horn works, swapping them is a quick way to check the pump relay.
Dutch
2001 GBM Landau 34' Class A
F53 chassis, Triton V10, TST TPMS
Bigfoot Automatic Leveling System
2011 Toyota RAV4 4WD/Remco pump
ReadyBrute Elite tow bar/Blue Ox baseplate