Welcome to the forum.
If its on a Ford F53 chassis. Fuel pump is inside the tank. The relay and fuse are in the fuse panel thats located above the radiator.. Look at the article I wrote, there is a photo with a yellow jumper wire. Thats where the relay is (I removed the relay and jumped the connections so I could pump fuel out of the tank)
In that same photo, there are two large 20 amp fuses just below the relay, the 20 amp fuse to the right is the fuel pump fuse..
F53 Replace Fuel Pump – 1999 Southwind 35S
When you turn the key from OFF to ON, the fuel pump should run for about three seconds.
The emergency fuel cutoff switch (collision G switch) is located just above the accelerator pedal. It has a red RESET button on it.