Code 18 - alarm - short circuit, Code 19 - alarm - disconnected, Code 20 - beacon - short circuit – JLG 10MSP Service Manual User Manual

Page 128: Code 18 - alarm - short circuit -24, Code 19 - alarm - disconnected -24, Code 20 - beacon - short circuit -24, See table 6-19, Ge 6-24, See table 6-20, See table 6-21