[rheavn]

Here are the results of the tests........................................................

Power post shut off.

Started coach engine, put on high idle and alternator worked fine showing 14.2 volts on the VMS--15.06 volts at battery isolator center alternator post.

Turned on genset.  Once it transferred in, the voltage began to drop until it reached battery voltage of 12.4V.  "Check alt" warning light lit.  Voltage at alternator post on battery isolator showed less than 3 volts.

Shut off genset.

Check alt light went out.  Voltage on VMS went back to normal 14V.  Voltage at alt post of batt isolator went back to 15V.

Pulled genset alt control wire.  Restarted genset.  Once it transferred in VMS voltage dropped to batt voltage and check alt light lit.  Voltage at battery isolator down to under 4 volts.

Shut off genset and alternator voltage returned to normal.

Any ideas......................................................