2008 h d rode king gas geage flasing emty (TANK FULL)
For a 2008 Touring bike with the ignition switch turned to IGNITION the fuel gauge is connected to +12 volts. Current flows through the gauge and the variable resistor in the fuel gauge sending unit to ground. The sending unit float controls the amount of resistance in the variable resistor. Inoperative gauges may be caused by several different circumstances: the sender or fuel gauge may not properly or sufficiently grounded; there may be a malfunction in the sender or in the fuel gauge; there may be a broken or disconnected wire from the ignition switch to the fuel gauge; there may be corroded connections at the fuel gauge.
Test the fuel gauge system by FIRST removing the gauge, THEN ground the fuel gauge sender Y/W wire located at the bottom of the gauge, turn the ignition switch to IGNITION and the fuel gauge must indicate FULL in which case it is functioning correctly in which case set a multimeter to the RXI scale and measure the resistance of the sending unit by placing one probe on (Y/W) and the other probe on the motorcycle ground or bare chassis point as a ground. If the fuel tank is full the reading should be 30-50 ohms while an empty tank should have a 240-260 ohm resistance value and a half full tank will be approximately 125-165 ohms. If a very high resistance or infinity is indicated on the meter, the sender may be "open" or not grounded. Check that the sender and the fuel tank are both grounded by placing one probe of a Multi-Meter on the sender flange and the other probe on the engine crankcase. The meter then must indicate one ohm or less. Replace the sender if one ohm or less was present and if a higher resistance is present, check for a poor connection on the ground wire.
If when the gauge did not indicate FULL when the fuel gauge sender Y/W wire was grounded with the ignition switch at IGNITION check the voltage to the (O/W) (+) and (BK) (-) wires of the fuel gauge connector and a correct reading will be equivalent to battery voltage. If battery voltage is not present check for a broken or disconnected wire. Replace gauge if wiring problem is not foun
Apr 16, 2014 |
2008 Harley Davidson FLHRC Road King...