1988 Johnson/Evinrude "CC" 40 thru 55 Models Service Manual, Page 271Get this manual
Running Test, Alternator OutputAll Models
Disconnect battery cables before proceeding with this check
1Remove the rectifier red lead from the terminal board2Wire to 40 amp ammeter in series with the rectifier red lead and the wiring harness red lead
!Illl.ftEf I1000 2000 3000 4000 5000 6000
Guard against any red wire, its terminals, or the ammeter coming in contact with engine ground while the engine is runningContact may cause arcing