Chad, if the ammeter is good n NOT stuck a magnet passed by it should make the needle deflect..... An ammeter is near a dead short continuois circuit across its terminals if its good.......If wired right if you turn on lights when engine isnt running IT SHOULD SWING OVER TO -DISCHARGE. If it swings to + charge its wired backwards n needs the wires swapped
An ammeter has ONLY ONE wire on its SUPPLY terminal which gets to the hot ungrounded battery post, often at the starter switch where the big battery cable atatches....
Its other LOAD terminal feeds hot batetry voltage to loads like lights (often the BAT input terminal on a light switch) (and ignition if a coil ignition) PLUS it wires to the BAT (NOT to the genny) terminal on the Cutout Relay.
The other GEN/ARM terminal on the Cutout Relay wires to the ARM post on the Genny.
Gennys FLD post wires to the charging resistor circuit on the Low/High charge type light switch.
After shes wired correct you need to Polarize the genny BEFORE you start her up.