Table 4-1: Cause And Remedy - Upright TM12 Service & Parts Manual

Troubleshooting

Table 4-1: Cause and Remedy

inoperable, Electric
Motor does not start.
inoperable. Electric
Motor starts when
control is actuated.
continues to run after
controls are returned
to the OFF position.
Steering inoperable
Work Platform will
Work Platform will
Work Platform will
not drive forward or
reverse. Lift function
No high speed drive.
No drive forward but
drives in reverse. Lift
function operable.
No drive forward but
drives in reverse. No
TM12 Work Platform - European
TROUBLE
All functions 1. Open control circuit Circuit Breaker
2. Blown Electric Motor Fuse
3. Faulty Battery Charger
4. Faulty Battery (ies)
5. Faulty Electric Motor
6. Faulty Motor Relay
7. Emergency Stop Switch failed open
All functions 1. Hydraulic Reservoir low
2. Faulty Hydraulic Pump
4. Proportional Valve
Electric Motor
Motor relay contacts fused together
1. Faulty Steering Switch
or functions
2. Mechanical damage
sluggishly.
3. Steering Valve stuck
4. Steering Cylinder piston seal leaking
1. Faulty Steering Switch
not steer right.
3. Faulty Steer Right Solenoid
1. Faulty Steer Switch
not steer left.
3. Faulty Steer Left Solenoid
1. Faulty Drive/Lift Selector Switch
2. Faulty Drive/Lift Valve
operable.
3. Mechanical failure
4. Worn Drive Motors
2. Faulty Down Limit Switch
3. Faulty Proportional Coil/Valve
1. Faulty Drive/Lift Selector Switch
2. Faulty Counterbalance Valves
1. Faulty Drive/Lift Selector Switch
lift function.
3. Faulty Up/Fwd Relay
PROBABLE CAUSE
3. Faulty Controller
5. Steering Relief
2. Faulty Diode
2. Faulty Diode
1. Faulty Relay
2. Faulty Controller
4.2 - Cause and Remedy
REMEDY
Check control circuit Circuit Breaker. Reset if open.
Check 175 amp Electric Motor Fuse. Replace if blown.
Check the voltage output of the Battery Charger. If less than 24
VDC, repair and replace.
After completely charging Batteries, test each Battery. Replace as
required.
While operating the steering function, check voltage across the
Electric Motor terminals. If 24 VDC is present, replace the Motor.
While operating the steering, check voltage across the coil
terminals of Motor Relay. If no voltage is present, proceed with
step 7. If 20 VDC or more, check continuity across the contact
terminals of Motor Relay while still operating the steering
function. If there is no continuity, replace the defective Motor
Relay.
With the Emergency Stop Switch in the ON position, check
continuity across the contacts. If none, replace.
Check hydraulic fluid level, top off as required.
Check pressure and delivery of the Hydraulic Pump. Replace if
required.
Check operation. Replace switch if required.
Check operation. Replace if required.
Check operation, replace if required. With 0 voltage at the coil
terminals of the Motor Relay (CR1) check continuity across the
contact terminals. If there is continuity, replace the Motor Relay.
Test Steering Switch for continuity. Replace if defective.
Inspect all steering components. Replace damaged parts.
Inspect Steering Valve. If spool is sticking, replace.
Check Steering Cylinder for leakage from one port to another.
Repair as required.
Adjust the relief valve, if not adjustable replace.
Test Controller Switch for continuity. Replace if defective.
Test Diode. Replace if defective.
Test Steer Right Solenoid. If the proper voltage is present and the
coil is not magnetized, replace.
Test Steering Switch for continuity. Replace if defective.
Test Diode. Replace if defective.
Test Steer Left Solenoid. If the proper voltage is present and the
coil is not magnetized, replace.
Check continuity of Drive/Lift Switch. Replace if defective.
Check the Drive/Lift Valve. If the spool is not shifting, replace the
valve.
Inspect Drive Motor shafts, hubs, and keys.
Check hydraulic pressure being delivered to the Drive Motors. If
sufficient, replace Drive Motors.
Test Relay (CR4). Replace if faulty.
Check Switch for continuity. Replace if faulty.
Test coil and valve. Replace if defective.
Test Drive/Lift Switch for continuity. Replace if faulty.
Check pressure of Counterbalance Valves. Replace or reset valves
as required.
Test Drive/Lift Switch for continuity. Replace if faulty.
Check operation of controller switch. Replace if required.
Test Relay. Replace if faulty.
Page 4-3