SkyTrak 8042 Service Manual - Manual (Page 836)

9.245 Model 8042, 10042, 10054 Legacy Rev. 10/03
Electrical System
b. Fuel Level Circuit Tests
For additional information refer to Section 9.8.36, “Fuel
Level Indicator Troubleshooting.”
If the fuel level indicator is suspected of giving a false
reading, perform the following checks:
1. Check for loose or defective wiring, faulty ground
connections, and corrosion on the fuel tank sender
and wiring lead.
2. If the fuel level indicator needle does not move after
the ignition key switch is turned to the RUN (6)
position, use a test lamp to determine whether
current is flowing from the ignition switch to the fuel
level indicator wiring connector behind the operator’s
instrument cluster. (The instrument cluster locking
ring can be unfastened and raised slightly to do this.)
If the fuel level indicator needle (1) does not move,
check the fuel tank for fuel.
If the fuel level indicator does not move and a faulty
or defective fuel level sender in the fuel tank has
been ruled out, and in addition, wiring and
connectors have been checked and ruled out, the
operator’s instrument cluster is defective and must
be replaced.
3. Check that the ignition terminal has current and that
the fuse in the fuse panel is not blown.
4. Check for broken, shorted, frayed, disconnected or
damaged wiring between the fuel level indicator
wiring at the operator’s instrument cluster, fuse and
relay panel, ignition key switch, and from the fuel
level sender on the fuel tank through the wiring in the
cab.
5. Check the fuel level sender. The resistance of the
fuel level sender is 31 ohms for a full tank of fuel,
101 ohms for 1/2 tank and 255 ohms for an empty
tank. A defective fuel level sender in the fuel tank
may also prevent the fuel level indicator from
moving.
Excessive fuel level indicator “fluctuation” may be caused
by loose wire connections or a defective fuel level sender
in the fuel tank.
A full tank reading at all times may occur if the wiring to
the fuel level sender in the tank is broken, if the sender is
not properly grounded or if the sender is defective.
If the fuel level indicator appears to be inaccurate, the fuel
level sender in the tank may be defective, or there may be
low voltage at the fuel level indicator connector to the
operator’s instrument cluster.
If the fuel level indicator fluctuates when other electrical
items are used, there may be a defective, corroded or
improper ground. Check the cab harness ground stud
under the dash, the engine to chassis ground, and the
negative (-) battery cable and ground stud cable.