40 Test Procedure
DWG NO. 4038
PLOW HARNESS
Testing Signals to Plow
This tests the connections of the plow harness. It assumes that the controller and under hood harness
have been tested and are known to be fully functional. The test device can be a 12 volt troubleshoot-
ing light. The red and black alligator clips of the Snowplow Tester power cable can also be used as a
troubleshooting light with the power “OK” light indicating 12 volts.
CAUTION: Lower the plow moldboard before working on it. Use extra caution if the plow
moldboard is stuck in the up position. Support the plow moldboard with a floor jack or
other suitable means to prevent the moldboard from accidentally dropping.
PLOW HARNESS TEST PROCEDURE
!
CAUTION: To prevent accidental plow operation perform the following steps.
A. Unplug power cable from grill
B. Turn connector 90 degrees.
C. Re-insert ground side ONLY.
DWG NO. 4225A
POWER CAUTION
Step
Action
Result
1.
Turn vehicle accessory power off.
2.
Connect the negative (black) lead of the test
device to a known vehicle ground. The posi-
tive (red) lead is used to check signals.
3.
Turn vehicle accessory power on.