Code 18 - alarm - short circuit, Code 19 - alarm - disconnected, Code 20 - beacon - short circuit – JLG SSV10 Service Manual User Manual

Page 110: Code 18 - alarm - short circuit -18, Code 19 - alarm - disconnected -18, Code 20 - beacon - short circuit -18, See table 6-19, Ge 6-18, See table 6-20, See table 6-21