INBOARD AND STERN DRIVE WATER <br />TEMPERATURE SYSTEM <br />1. To test gauge, voltage from I to G terminals must be 10-16 VDC. No wire on S terminal. Gauge pointer <br />should rest below 120ºF. Next, connect the S terminal to the G terminal (leave I and G terminals <br />connected). The gauge pointer should rest above 240ºF. <br />2. The resistance of the sender can be measured to determine the sender's correct operation. Remove <br />wire to gauge. Connect an ohmmeter to terminal of sender and to engine block. Approximate values are: <br />75ºF (room temperature) = 550 to 750 ohms; 212 degrees = 55 ohms. You will get half these values on a <br />dual gauge sender. <br />3. If sender is shorted (0 ohms), gauge will read above 240ºF. <br />4. If sender has infinite resistance (Open), gauge will read below 120ºF. <br />5. If the gauge reads lower than expected, was sealer used on the sender threads (see picture)? <br />6. The accuracy of the system (gauge, sender, voltage range) can vary as much as +/- 16º at 180ºF. <br />7. Pipe extenders to plumb both a sender and temperature switch (for horn or warning light) from one port is <br />not recommended. The amount of weight extended on the fitting of a vibrating engine could cause fatigue <br />breakage. Also, the sender is removed from water flow and will probably read cooler. <br />8. Teleflex does not offer senders for metric threaded ports. <br />9. Dual Station installations: <br />When replacing one gauge in a two station installation, the second gauge may need to be replaced as <br />well. Mixing two gauge manufacturers to one sender may cause an error in both gauges. <br />If one gauge fails the second gauge will read much higher than expected. <br />If the sender fails "open," both gauges will read below 120ºF. <br />If the sender fails "short," both gauges will read above 240ºF. <br />10.Twin engines - it may be helpful in troubleshooting to switch either the senders or the gauges from engine <br />to engine.
