Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 344Get this manual
Horn Does Not Sound Low Oil Warning When Oil Level Is Below 14 Full
Horn does not sound
1: Disconnect connector from tank receptacle and install Jumper wire between pmsI
Horn sounds Go to TEST 2
Go to "Horn Does Not Sound When AutoSlend is Turned Upside Down