1993 Johnson Evinrude "ET" 9.9 thru 30 Service Manual, P/N 508282, Page 36Get this manual
Warning Horn Test To avoid possible powerhead damage, be sure the warning horn is in operating conditionIt is advisable to check the horn at the start of each boating season and periodically during the season
[!] 1Disconnect bullet connector at temperature switch2Connect engine harness half of bullet connector to clean engine ground3With the key switch in the ON position, the horn should soundIf the horn does not sound, but other electrical components function correctly, the horn or wiring may be damagedRepair or replace as requiredRefer to Temperature Switch Test, Section 4