REPAIR STEPS
SOLUTION
DIAGRAMS
PROBLEM
MI91.2236
26JUN98
REFER TO MP85.5043
REFER TO MP85.5043
REFER TO MP65.0
WHITE GROUND
BROWN ACC
5 AMP
10 AMP
10 AMP
5 AMP
ACC FUSE
5 AMP
10 AMP
10 AMP
YELLOW IGN
(WHEN APPLICABLE)
REFER TO MP85.5060
Part 4 cont’d.
b. The low battery
indicator light comes
on.
Push the "OFF" button, then the "I" button one time. Check that Term-
inal 8, Relay A, is properly grounded. Terminals 1, 2 and 3 should
all have +12 volts. Terminal 2 is the main power supply from the bat-
terries. Check batteries, connections, battery grounds etc. if +12 is not
present on Terminal 2. If Terminal 1 has +12 but not Terminal 3, re-
place Relay A. If Terminal 1 does NOT have +12, check the 5 amp
c. The pump does
not come on.
After pushing the "I" button the second time, if the pump does not run,
the indicator light above the "I" button will flash approximately 12 sec-
onds. The system then shuts down. The light must be flashing to make
the following checks. Check that Terminal 7 of Relay B is properly
grounded. Check for +12 volts on Terminals 5 and 6 of Relay B. If +12 is
present on Terminal 5 but not 6 replace Relay B. If +12 is present on
both 5 and 6, the pump is the problem. Check that the pump is se-
REFER TO MP85.5110
REFER TO MP85.5115
REFER TO MP85.5120
d. Pump runs under
no load and nothing
happens.
Disconnect the pressure tube between the manifold and shuttle valve.
Connect the pressure gauge to the fitting in the manifold. (Not the
shuttle valve.) Turn the pump on for 5 to 10 seconds. The pressure
should be approximately 3500 psi. If there is low pressure, change the
power unit. If the pressure is ok, change the shuttle valve.
e. A jack is vertical
but its red warning
light is not lit.
Check that each jack has the proper color coded wire to its warning
switch. If so, unplug the jack warning switch for the light not lit. Ground
the wire going to the control box. If the light comes on, check the
ground for the warning switch, then replace the switch. If the light does
NOT come on, unplug the orange MTA connector for the warning switch-
es at the control box. Use a 12 volt test light connected to ground.
Touch each pin in the control box. If the red warning lights work prop-
erly, the signal wire from the jack is bad. If the red lights do NOT come
on, replace the control box.
#10 BLACK
POWER WIRE
RED MASTER RELAY
BLUE HAND/AUTO PARK SWITCH
GRAY PUMP RELAY
MASTER WARNING
LIGHT
POSITIVE
VOLTAGE
LF WHITE
RF RED
RR BLACK
LR GRN
JACK WARNING/
PRESSURE SWITCH
INPUTS
PRESSURE
TUBE
ACC fuse. If the fuse is ok, check the red wire in the 6 pin UML at the
control box. If +12 is present at the control box, the problem is the red
wire. If +12 is not present at the control box, replace the control box.
If the fuse is blown, the problem may be a shorted red wire or a bad
master relay. If Terminals 1, 2 and 3 all have power, check the three
black wires in the 6 pin UML at the control box. (This must be checked
while the 6 pin UML is plugged into the control box.) If +12 is not pres-
ent, the #10 black wire is broken or the 60 amp fuse on the #10 black
wire at the relay is blown. If +12 is present on the black wire, check
the voltage on the black wire at the control box while the "I" button is
pushed a second time. Voltage is also monitored on the brown (or
yellow) wire in the 3 pin UML connector. If the voltage drops below
8.5 to 9.0 volts, the low volts indicator will come on. The problem could
be a bad battery, a bad pump motor, loose connection or bad wires.
If the voltage does NOT drop, replace the control box.
curely mounted and grounded to the frame of the vehicle. If +12 is
NOT present on Terminal 5, check the 5 amp pump fuse. If the fuse
is not blown and +12 is not present on the gray wire in the 6 pin UML
at the box, replace the control box. If +12 is present at the control box,
the problem is the gray wire. If the fuse is blown, the gray wire is short-
ed to ground or the pump relay is bad.
(PUMP RELAY)
RELAY B
GRAY