TROUBLESHOOTING AND ELECTRICAL
SYSTEM: DIESEL VEHICLES
Test Procedures
12
TEST PROCEDURE 31 – Fuel Level Sending Unit
See General Warnings, Section 1, Page 1-2.
WARNING
• To avoid the possibility of fire or explosion, make sure the fuel tank cap is securely in place while
performing this test procedure.
1.
Disconnect battery.
See Side-Post Battery: Disconnecting the Battery – Gasoline/Diesel Vehicles on page
1-3.
See Top-Post Battery: Disconnecting the Battery- Gasoline/Diesel Vehicles on page 1-4.
2.
Disconnect the orange wire (w104) from the center post of the fuel level sending unit.
3.
With a multimeter set to 2k ohms, place the red (+) probe on the center post of the sending unit. Place the black
(–) probe on the ground connection of the sending unit
2100
Figure 12-32
Fuel Level Sending Unit Test
4.
The following resistance readings (in ohms) should be indicated, depending on the position of the float inside
the fuel tank. The resistance reading will vary according to the exact position of the float. The following table
may be used as a guideline to determine if the fuel level sending unit is operating correctly. Make sure the float
is at the surface of the fuel in the tank.
_
FLOAT POSITION
RESISTANCE READING
FUEL GAUGE READINGS
Lower position (tank empty)
240 ±20 ohms
Empty
Center position (tank half full)
120 ±20 ohms
Half full
Upper position (tank full)
60 ±20 ohms
Full
5.
If the readings are within the specifications listed in the preceding chart, the fuel level sending unit is working
properly. If the readings are incorrect, the fuel level sending unit has failed and the fuel tank must be replaced.
See Fuel Tank Removal on page 16-15.
6.
If the readings are correct and the fuel gauge does not function correctly, leave the battery disconnected and
check the continuity of the following:
– Orange wire (w104 and w20) from the fuel level sending unit to the fuel gauge/hour meter.
– Blue wire (w25) and purple wire (w37) from the fuel gauge/hour meter to the key switch.
2016 Carryall 1500/1700 and XRT 1550 Maintenance and Service Manual
Page 12-39
Summary of Contents for Carryall 1500 2016
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