2006 Honda TRX680 Rincon Factory Service Manual, Page 550Get this manual
LIGHTSMETERSSWITCHES Temperature indicator does not go off with the fan motor stops Remove the left engine side cover (page 3-17)Disconnect the ECT sensor 2P (Black) connector
(BLACK) CONNECTOR Turn the ignition switch ON and check the temperature indicator If the indicator comes on, then goes off, check the ECT sensor (page 23-14)FGA model shown: TEMPERATURE INDICATOR
If the indicator comes on and stays on, disconnect the connector from the EOT sensor and check the temperature indicator- If the indicator goes off, check the EOT sensor (page 23-15)- If the indicator stays on, check for short circuit in the White and Greenred wire on ECT sensor wire or Yellow and Greenred wire on EOT sensor