Scrub System
87
Service Manual – SC1500
Troubleshooting
Problem
Cause
Correction
Brush Motor not
running
No voltage to the K2 Brush
Contactor coil
1. Check the voltage on pin J3-13 on the A1 Control
Board. The signal, referenced to ground, should
be 24.3v with the Brush Motor off, 0.2v with the
Brush Motor on.
2. Check the wiring from the Key Switch to the K2
Brush Contactor coil and repair as necessary.
No voltage through the
contacts on the K2 Brush
Contactor
1. Check circuit breaker CB4 and reset if necessary.
2. Check the coil resistance on the K2 Brush
Contactor. If the coil resistance is not 58.3 ohms
±10%, replace K2.
3. Check the continuity through the contacts on the
K2 Brush Contactor with the coil energized. If the
circuit is open, replace K2.
4. Check the wiring from battery positive to circuit
breaker CB4, and from CB4 to the K2 Brush
Contactor and repair as necessary.
5. Check the wiring from the K2 Brush Contactor to
the Brush Motor and repair as necessary.
6. Check the Brush Motor ground connection and
repair as necessary.
Scrub Deck Actuator
not running.
No voltage to the Deck
Actuator Motor
Check the voltage on pins J1-9 and J1-10 on the A1
Control Board. The signals, referenced to ground,
should be as follows:
Pin J1-9:
•
2.1v or 3.8v – actuator at rest
•
0.2v – actuator extending
•
22.9v – actuator retracting
Pin J1-10:
•
2.1v or 3.8v – actuator at rest
•
22.9v – actuator extending
•
0.2v – actuator retracting
Scrub Deck not
being lowered to the
vacuum-only position
No signal from Position Switch
1, S7, to pin J2-12 on the A1
Control Board.
Check the voltage on pin J2-12 on the A1 Control
Board. The signals, referenced to ground, should be
4.99v with the switch open and 0.03v with the switch
closed.
Scrub Deck not being
lowered to the normal
scrub position
.
No signal from Position Switch
2, S6, to pin J2-11 on the A1
Control Board.
Check the voltage on pins J2-11 on the A1 Control
Board. The signals, referenced to ground, should be
4.99v with the switch open and 0.03v with the switch
closed.
