Determine whether the problem is the pump itself or the aircraft wiring.
Disconnect the positive wire from the fuel pump.
If there is a capacitor, disconnect it also.
Install a 5 amp inline fuse between another 12 volt power source and the fuel pump.
If the new inline fuse blows, the problem is the fuel pump.
If the pump runs fine, the problem is in the aircraft wiring or capacitor if installed.
Check wherever the fuel pump supply wire passes through sheet metal,
especially the instrument panel bottom and over the rudder pedals.