That there is your standard dead battery/bad cell/corroded battery posts/corroded cables/corroded cable clamps/loose clamps/corroded connection at starter/failing ground strap or cable/failing foot starter switch, possible bad starter ...........or maybe something else.
1. Check battery for 12.6V at rest. report number
2. Check battery voltage during foot pedal press, see if voltage drops way down or no change. report number.
3. Check all those connections
4. 5 speed? Electric fuel pump?
5. If numbers not good at battery check, take battery to good FLAPS for load test.
6. Report above to continue tests. Use volt meter/multimeter set to DC volts.
Ignition switch not involved
Charging system not involved
The bad battery or corroded termination breaks down when starter draws 450 Amp +. You are noticing the pump because it's the only thing that makes noise when ignition switch is on. If you had headlights on, they would go off also.
