80
MicroController Control System
Troubleshooting
PROBLEM 27
Auxiliary lighting and/or alarm does not function
correctly. Lift and drive operation normal.
POSSIBLE CAUSE
Open fuse; Faulty wiring; Defective switch; Shorted
load; Open load; Loss of input voltage to DC-DC
converter; Defective DC-DC converter.
CHECKS
Connect the battery and close the key switch.
Measure from the DC-DC converter 12V positive
terminal to the 12V negative terminal.
No voltage
Voltage
Voltage
Voltage
output
above 13V
below 11V
11 to 13V
Check for voltage on the load
side of the auxiliary switch.
11 to 13 volts
0 volts
Repair or replace open wire going
to battery negative.
Check for short
circuits; Replace
auxiliary fuse.
Check for voltage at the negative connection
of the load.
0 volts
11 to 13 volts
Repair or replace open wire from
fuse or replace detective switch.
Repair or replace open wire from
the auxiliary switch or replace the
defective auxiliary component.
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With the faulty auxiliary circuit
activated, check for voltage on
load side of the auxiliary fuse.
11 to 13 volts
No voltage
Summary of Contents for B20S-3
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