TROUBLESHOOTING THROTTLE CIRCUIT
Engine does not throttle up in full throttle position
Voltage checks:
(1) 48 to 3 - defective throttle switch or open wire 48 to relay R4
(2) 4 to 3 - defective throttle breaker or breaker tripped - if tripped, check for bind in throttle linkage
(3) 5 to 3 - defective R4 relay or relay socket - if voltage is present on throttle solenoid, check for faulty solenoid
Throttle works in full but not in soft-start
One or both track switches in travel FWD-REV limit switch in FWD.
Voltage checks:
(1) 46 to 3 - defective FWD-REV limit switch
(2) 47 to 3 - defective R6 and/or R7 relay or relay socket
(3) 48 to 3 - defective soft-start side of throttle switch
TROUBLESHOOTING TRAVEL CIRCUIT
Brakes do not release
Track switches in neutral position.
Voltage checks: (LH side)
(1) 35 to 3 - if present, LH track switch is defective or 35 is shorted to 12 VDC
(2) 25 to 3 - defective R5 relay or relay socket
(3) Check for approximately 6 VDC from 26 to 27 - if not, adjust 5 ohm resistor until 6 VDC is present or release
begins
(4) Check for 6 VDC from 26 to 27 on brake coil - if present, check for defective brake coil - coil should have 3
ohms resistance
Voltage check: (RH side)
(1)
38 to 3 - if present, RH track switch is defective or 38 shorted to 12 VDC
(2)
31 to 3 - defective R8 relay or relay socket
(3)
Check for approximately 6 VDC from 32 to 30 - if not, adjust 5 ohm resistor until 6 VDC is present or release
begins
(4)
Check for 6 VDC from 32 to 30 on brake coil - if present, check for defective brake coil - coil should have 3
ohms resistance
Brakes do not energize
Track switches in brake position
Voltage checks: (LH side)
(1) 35 to 3 - defective LH track switch
(2) 27 to 3 - defective R5 relay or relay socket
(3) Check for 6 VDC from 27 to 26 - defective or misadjusted 5 ohm resistor
(4) Turn travel circuit breaker OFF to see if permanent magnet in brake works
Voltage checks: (RH side)
(1)
38 to 3 - defective RH track switch
(2)
30 to 3 - defective R8 relay or relay socket
(3)
Check for 6 VDC from 27 to 26 - defective or misadjusted 5 ohm resistor
(4)
Turn travel circuit breaker OFF to see if permanent magnet in brake works.
(CONTINUED)
Page 24