Simplicity AGCO Allis 2000 Series, Service & Repair Manual

Page: 113 / 312

7 - 45
7 Electrical System Service
Component Tests
OHMS INCREASE
OHMS DECREASE
W. Fuel Level Sensor Test
1. Remove seat deck (refer to Section 15, SEAT DECK
SERVICE).
Figure 54. Fuel Level Sensor Signal Test
A. Sensor C. Ground
Terminal
B. Signal Terminal D. Signal Wire
A
V. Fuel Level Signal Test
This test should be done before you fill the fuel tank,
when the tank is near empty. If it is full, empty the tank
before proceeding with this test.
1. Remove seat deck (refer to Section 15, SEAT DECK
SERVICE).
2. Set the volt meter to dc volts.
3. Connect the black negative (-) test probe to the
ground terminal (C, Figure 53) and the red positive
(+) test probe to the signal terminal (B) to measure
the voltage drop across the sensor.
4. The dc voltage level read on the volt meter when the
tank is empty should be about 1 to 4 volts dc.
5. Slowly begin filling the fuel tank with the proper fuel
while watching the voltage level. As the fuel tank is
filled, the voltage level should increase.
6. If the voltage does not change or is at or near zero
volts dc, remove the signal wire (D, Figure 54) from
the fuel level sensor, which is the center wire and ter-
minal (B).
7. Connect the black negative (-) test probe to ground
terminal (C) or the negative (-) battery post and the
red positive (+) test probe to the signal wire (D).
8. The volt meter should read approximately 12 volts dc.
If the voltage is near zero or below 11 volts dc,
replace the instrument panel. If the voltage is ok, pro-
ceed to the Fuel Level Sensor Ohm Test.
B
Figure 55. Fuel Level Sensor Ohm Test
A. Sensor Frame
D. Signal Terminal
B. Float E. Variable Resistor
C. Ground Terminal
C
2. Remove the fuel level sensor assembly.
3. Using an ohm meter, measure the resistance across
the ground terminal (C, Figure 55) and signal terminal
(D).
4. Move the float (B) up and down, the resistance
should change as you move the float. The range is
from 30 ohm when the float is in the full position to
300 ohm when the float is in the empty position.
D
A
E
Figure 53. Fuel Level Sensor Volt Test
A. Sensor
C. Ground Terminal
B. Signal Terminal
C
B
C
D
A
B
Not
for
Reproduction