Swing arm fuel tank sending units are by far the most popular on the market today, but the new reed style is growing in popularity. The swing arm style is less expensive and can be adjusted to fit most tanks. Moeller offer two size a 4 -12” model and for tanks up to 24”. These can be cut to fit for less than 12” or bolted together for 12 plus inches to get the desired tank depth. The reed style sending unit must be order in the proper length for a desired tank depth. This style is also a little more expensive, but more accurate when fuel sloshing occurs. The article below is for help if you having trouble with a swing arm style sender. Fuel gauge not working? Is it the fuel tank sending unit or the gauge itself? Hers is a simple trick to check to see where the problem. • First locate the sending unit in the tank. You should see 2 wires one on the center stud (power wire +) and the other wire connected to a tab or under a screw holding down the sender (ground wire - ). • Turn the ignition switch to the power on position (energizing the gauges not starting the engine). • With the ignition switch on. Go back to the sending unit and with a screwdriver lay it across the center stud to the ground wire. This will complete the circuit and if the sending unit is bad, but the gauge and wiring are good the gauge will read full. If the gauge needle doesn’t move the gauge or wiring is bad. Replacing a bad fuel sender is easy. • Disconnect the battery or turn off you battery switch if applicable. The sender is held in place by 5 machine screws. • Remove the power and ground wire. • Remove the five machine screws holding the sender in place. The bolt pattern is a marine standard so for replacement we just need to know the length of the sender. • When removing the fuel sender and gasket take care to make sure which direction the arm swings. • Check the length of the sender. Replacement senders are designed to be cut or bolted together to make the desired length. • Reinstall your new sender with gasket, again make sure the arm swings in the proper direction. Install your 5 screws torque tight, reconnect the wires, and reconnect the battery. • Installation complete.