What is your Engine Model, Spec., and Serial numbers?
I assume it has a Denso or a Delco solenoid shift starter on the engine and not an inertia drive which would use a seperate starter solenoid.
Assuming it is the solenoid shift style, you will have the main battery cable (red) go from the battery directly to a starter post. On this same post you will probably have a smaller wire that goes to feed the machine also.
The second post will have a braided "wire" from it and loop inside the starter.
The third "terminal" is a 1/4" push on terminal with a blue wire on it...
Disconnect this blue wire and using your DVM check for battery voltage from this wire to ground in the START position of the key... If you have battery voltage on that blue wire, then you have a starter problem. If you do NOT have battery voltage on that blue wire, then you have a problem in that circuit back on the main harness/engine connection or on the unit somewhere.