Western HTS Mechanic's Manual page 67

TROUBLESHOOTING GUIDE
SOLENOID COIL ACTIVATION TEST (SCAT)
NOTE: This MUX-plow diagnostic
harness kit can be used with
or without the snowplow
connected to a vehicle. Follow the
appropriate instructions for each
testing situation.
WARNING
Lower blade when vehicle is
parked. Temperature changes
could change hydraulic
pressure, causing the
blade to drop unexpectedly
or damaging hydraulic
components. Failure to do
this could result in serious
personal injury.
On-Truck Testing
Remove the vehicle ignition key and
put the vehicle in PARK or in gear
to prevent others from starting the
vehicle during testing.
1. Disconnect the snowplow and
vehicle battery cables, then
remove the hydraulic unit covers.
Lit. No. 41467, Rev. 01
2. Unplug the snowplow connectors
from ports A and B of the plow
module.
Plow Module (on hydraulic unit)
LED
29290-2
Diagnostic
Harness
4-Position
Control
Connector
3. Connect the diagnostic harness
connectors A and B to the
matching ports on the plow
module (A to A and B to B).
4. Plug the connectors removed
from the plow module into the
matching connectors on the
diagnostic harness (A to A and
B to B).
5. Connect the snowplow control into
the 4-position control connector
either in the cab of the vehicle or
on the diagnostic harness.
6. Reconnect the snowplow and
vehicle battery cables.
NOTE: If you connect the control
inside the cab of the vehicle,
Plug
the engine does not need to be
running, but the vehicle ignition
key must be turned to the "ON"
position before proceeding. If
you connect the control to the
diagnostic harness, the key
should be left out of the ignition.
7. Turn the snowplow control ON
and perform a SCAT. See the
following chart for solenoid
numbers and functions. See
the beginning of this section for
instructions on performing a
SCAT.
NOTE: The green LED on the
diagnostic harness will illuminate
when the motor relay function is
activated. This light only tests the
plow module's motor relay output.
Refer to Motor and Motor Relay
Test section for instructions on
properly testing a motor relay.
Solenoid Coil Activation
Test (SCAT) Chart
Control Component(s)
Function Activated
Raise S3 Motor Relay
Lower S1
Angle Right S2, Motor Relay
Angle Left S2, S3, Motor Relay
8. After completing the SCAT,
turn the snowplow control and
the vehicle ignition OFF, then
disconnect the snowplow and
vehicle battery cables.
9. Perform any required repairs and
retest as needed. Make sure to
disconnect the snowplow and
vehicle battery cables before
removing the diagnostic harness.
April 15, 2021
67