1999 "EE" Evinrude 200, 225 V6 FFI Outboards Service Manual, P/N 787025, Page 141Get this manual
Auxiliary Battery
INote Disconnect all accessories from the auxiliary batteryAuxiliary battery must read minimum of 8V2 volts at the beginning of these testsThe auxiliary battery must remain connected to the outboard during the tests1Check battery ground cable for continuity
2With key OFF, check battery voltage at auxiliary battery, then check voltage at auxiliary battery connection If the readings are not the same, replace wire to auxiliary batteryThe auxiliary battery wire must be at least 10 gauge and it must be protected by 50 amp fuse or circuit breaker at the battery
3With engine running at 1000 RPM, voltage must read higher than in Step and increase steadily to approximately 14'12 volts as the engine RPM increases4No increase, turn key to OFF and check redblack wire between rectifierregulator and auxiliary battery terminal for continuity Continuity indicates rectifierregulator problem No continuity indicates wire problem40-Volt Circuit 1Check battery ground cable for continuity