2.3 Basic Troubleshooting - Electrical System
Problem
Possible Cause
Remedy
"STABILIZERS
NOT RETRACTED"
indicator does not
go out when
stabilizer is
retracted
Proximity switch improperly
adjusted
Proximity switch defective
Relay CR4 defective
Readjust switch.
Replace defective switch.
Replace defective relay.
Pawls do not
disengage ratchet
teeth upon
command from
SAFETY RELEASE
switch
Defective unlock solenoid on
stair or A-frame locking
mechanism
Refer to "Hydraulic
System/Adjustable Section
"...will not operate" at
beginning of this table.
No response from
any electrical
command
Open circuit
Defective 70-amp main power
supply circuit breaker
Defective main power relay
CR1
Check wiring for continuity.
Replace circuit breaker.
Check for voltage. Replace
relay.
"Stabilizer Not
Retracted"
indicator lamp
does not light
when stabilizer is
extended
Defective indicator
Limit switch actuators stuck
Limit switches improperly
adjusted
Limit switches defective
Defective circuit breaker
Replace indicator.
Check switch actuators.
Replace switch if defective.
Readjust switches.
Replace switches.
Replace appropriate 20-amp
circuit breaker
"LIGHTS ON"
indicator light or
platform spotlight
does not illuminate
when switch is on
Defective spotlight lamp and/or
spotlight indicator lamp
Defective switch
Defective 25-amp circuit
breaker
Short in wiring
Replace lamp.
Replace switch.
Replace circuit breaker.
Check wiring and repair.
Stair lights,
indicator light
and/or stair tread
illuminating lights
do not illuminate
when "LIGHTS"
switch is on
Defective lamp
Defective switch
Defective 25-amp circuit
breaker
Open circuit
Short in wiring
Replace lamp.
Replace switch.
Replace circuit breaker.
Check continuity and repair.
Check wiring.
CHAPTER 2 MAINTENANCE
SEPTEMBER 30, 2008
2 TROUBLE SHOOTING
PAGE 3
Truck Mounted Passenger Stair TMPS-200
Manual No. 307559
