1. Check for loose connections on the alternator
2. Check the battery it should gives you 6 volts if not the correct voltage replace the battery.
3. Disconnect power cord
4. Remove black wire from b+ terminal on the alternator
5. Remove the brown wire from the field terminal
6. Place a short wire with alligator clips from the b+ to the field terminal
7. Step on machine for at least 15 seconds
8. If you have full resistance alternator is good. If you lose resistance alternator needs replaced.