Small Engines (Lawn Mowers, etc.): BRIGGS/STRATTON 18 HP VANGUARD, briggs stratton, vdc battery

Question
Eric,
Can't seem to find the right connection for the charging circuit.  Engine starts and runs but as soon as I remove the 12 vdc (battery), it shuts down.  Three wires coming from the rectifier block (two yellow which are connected and a red which is unconnected).  There is no 12 volts at this red wire.  Help.

Answer
http://www.briggsandstratton.com/miscpdfs/RNT/alternator_replacement.pdf

The above link contains information on Briggs alternators.  What is the engine mounted on?  A riding mower?  Is there fuel shut-off solenoid on the carburetor?
Let me know.
Eric