Troubleshooting Teleflex Fuel Gauges
Does the Gauge Work?
To see if the gauge is operating correctly:
- Remove the gauge's sender wire. Turn on the
power. The pointer of whatever gauge you are
checking should be at the position shown in the
upper portion of the diagram at right.
- Next, take a short wire and connect to sender
terminal and ground terminal (shorting sender
terminal to ground).
Gauge pointer should be at the position
shown in the lower portion of the diagram.
- To test senders, the resistance values are
shown at minimum and full gauge scales.
Fuel Systems (Marine)
- Voltage - "I" to "G" terminal - 10 to 16 volts.
- Test gauge as follows: Connect "hot" wire to
the "I" terminal and ground wire to "G" terminal.
Remove sender (usually pink) wire from back
of gauge. Gauge should read below "EMPTY".
Next, add a short wire from the gauge's "S"
(sender) terminal to ground. Gauge should read
above "FULL." If the pointer sweeps back and
forth, gauge is OK.
- The sender can be tested by checking its
resistance with a volt/ohm test meter (use
analog meter) as follows:
- Remove sender (usually pink) wire from sender.
- Connect two test meter wires to two sender
terminals (or center terminal & flange if sender
has only one terminal).
- Move float arm by hand. Approximate values:
Empty = 240 ohms, 1/2 = 103 ohms,
Full = 33 ohms.
(Teleflex sender: rheostat housing installed
upside down will cause gauge to read
backwards. See illustration.)
- Sender resistance tolerances at full may cause
the gauge to read 2-3 pointer widths either side
of the full mark.
- The sender will accurately operate only one
standard gauge at a time. It is not designed for
dual station use with standard gauges.
- Gauge will not operate accurately from more
than one sender at a time. Some installations
use a switch to connect one gauge to various
tanks, one at a time.
- Sender will not operate in water tanks. Rheostat
will become electrically "open".
- Be certain sender dimensions are adjusted per
the instruction sheet.
- If sender is "open" (infinite resistance) gauge
will read below empty. If sender is shorted (0
resistance) gauge will read above "FULL".
- Some "bowing" of the flange may occur when
the 5 mounting screws are tightened. The
gasket under the flange will normally seal the
flange properly, but do not overtighten the
- Sender must be grounded, or gauge will always
- If sender is installed in a tank not designed for
a sender, care must be taken to seal screw
threads. Sealant under screw head is also
advisable. Sealant must withstand gas and