1997 Johnson Evinrude "EU" 9.9 thru 30 2-Cylinder Service Manual, P/N 507263, Page 328Get this manual
WATER TEMP Circuit 1Separate the connector between the engine harness and the temperature switch[] 2Using jumper wire, connect the engine harness tan lead to clean engine ground3Turn the key switch to ON positionAfter the normal self-test sequence, the gauge WATER TEMP light should stay on If WATER TEMP light is not on, troubleshoot tan circuit for an open in the engine harness or the instrument harness4On engines, test both temperature switch tan circuits5To test the temperature switch itself, refer to Temperature Switch, Section 46Turn the key switch OFF and reconnect all circuits disconnected during these tests
Circuit Verification, CIVIC Tester, PIN 437274
Verify the condition of the boat modular wiring system using OVIC Tester, PIN 437274Power to the tester is supplied by: 110 VAC adapter supplied with the tester