1974 Johnson 135 HP Outboard Motors Service manual, Page 103Get this manual
ALTERNATOR CIRCUIT TROUBLESHOOTING S EP1
UNDER HARGED BA'ITERY
AMMETER
12VOLT BATTERY I
I :IGN ITION SW ITCH
a, Check condition of batterySee Specifications Section 7bCheck all connectionsThey must be tight &
cleancCheck electrical load on systemTotal urrent
TO ACCESSORIES
12 VOLT BAT TERY
engine and accessories must not be
greater than ampsd, Inspect cables and leads (or worn insulationALTERNATOR OUTPUT CHECK