Maxon MXT-25, Maintenance Manual

Page: 52 / 61

1
1921 Slauson
A
ve. Santa Fe Springs, CA. 90670 (800) 227-41
16 F
AX (888) 771-7713
52
PLATFORM WILL NOT LOWER, LOWERS TOO SLOWLY, OR TOO QUICKLY
1.
Connect voltmeter
(+)
lead to motor solenoid terminal
“B”
and the
(-)
lead to the
ground wires connection on pump
(FIG. 52-1)
. Verify that full battery voltage is at
“B.”
Recharge the battery if voltmeter indicates less than 12.6 volts DC, or 25.2
volts DC for 24 volt system.
3.
Check if the
“D”
terminal and
“S1”
(lowering) solenoid valve are getting bat-
tery voltage
(FIG. 52-1)
. Connect voltmeter negative
(-)
lead to ground
(-)
wires
connection on pump and positive
(+)
lead to the
“D”
terminal
(FIG. 52-1)
. Hold
control switch in the
DOWN
position. If voltmeter shows a much lower reading
than +12.6 volts DC, or 25.2 volts DC for 24 volt system, or a reading of 0 volts,
check for faulty control switch and wiring. Check battery cable and ground wire
connections in pump assembly and aux battery box (if equipped) for tightness
and cleanliness. Check coil resistance to make sure it is within speci
fi cations.
Next, connect voltmeter
(+)
lead to
(+)
terminal on the
“S1”
(lowering) solenoid
valve
(FIG. 52-1)
. Voltage may be as low as 10.5 volts DC, or 21 volts DC for
24 volt system. If voltmeter shows a much lower reading, or a reading of 0 volts,
check for faulty control switch and wiring, battery cable, ground wire connections
in pump assembly, and pump motor.
2.
Check for structural damage or poor lubrication. Replace worn parts.
VALVE “S1”
LOWERING
SOLENOID VALVE
SOLENOID
SWITCH
TERMINAL “B”
BATTERY (+)
GROUND (-) WIRE
CONNECTION
TERMINAL “D”
COIL DRIVE (+)
VOLTMETER (-)
LEAD)
FIG. 52-1