18
External Motor Testing
MOTOR (MODEL EJ4-4001 AND EJ8-4001A)
TEST PROCEDURE 1 – Internal Short Circuits
See General Warnings on page 1-1.
1.
Disconnect the battery cables and discharge the controller as instructed.
See WARNINGS “To avoid
unintentionally starting...” and “After disconnecting the batteries, wait 90 seconds...” in General
Warnings on page 1-1.
2.
Disconnect wires from terminals on motor using two wrenches to prevent posts from turning.
3.
With a multimeter set to 200 ohms, place black (–) probe on motor housing. Scratch through paint to ensure a
good connection. Place red (+) probe on A1, A2, S1, and S2 terminals respectively. Multimeter should indicate no
continuity between the motor housing and all individual terminals. If readings are incorrect, motor will need to be
removed from the vehicle and repaired by a qualified technician.
See Motor Removal on page 18-3.
3.1. An incorrect reading from the A1 or A2 terminal indicates three possible problems: a grounded A1 or A2
terminal, a grounded wire in the brush area, or a grounded armature/commutator. An incorrect reading for
the S1 or S2 terminal indicates a possible grounded S1 or S2 terminal or field coil.
4.
If readings are correct, reconnect the motor wires.
See Motor Installation on page 18-14.
5.
Place the Tow/Run switch in the TOW position and connect the batteries, positive (+) cable first. Tighten battery
terminals to 110 in-lb (12.4 N·m) and coat terminals with Battery Terminal Protector Spray (CCI P/N 1014305) to
minimize corrosion.
TEST PROCEDURE 2 – Armature Circuit Open
See General Warnings on page 1-1.
1.
Disconnect the battery cables and discharge the controller as instructed.
See WARNINGS “To avoid
unintentionally starting...” and “After disconnecting the batteries, wait 90 seconds...” in General
Warnings on page 1-1.
2.
Disconnect wires from the A1 and A2 terminals on the motor using two wrenches to prevent posts from turning.
Set a multimeter to 200 ohms and place the red (+) probe on the A1 terminal and black (–) probe on the A2
terminal. The multimeter should indicate continuity. If the reading is incorrect, a possible open or poor contact in a
brush assembly and/or open armature windings may be the cause. The motor will need to be removed from the
vehicle and repaired by a qualified technician.
See Motor Removal on page 18-3.
3.
If reading is correct, reconnect the motor wires.
See Motor Installation on page 18-14.
4.
Place the Tow/Run switch in the TOW position and connect the batteries, positive (+) cable first. Tighten battery
terminals to 110 in-lb (12.4 N·m) and coat terminals with Battery Terminal Protector Spray (CCI P/N 1014305) to
minimize corrosion.
TEST PROCEDURE 3 – Field Circuit Open
See General Warnings on page 1-1.
1.
Disconnect the battery cables and discharge the controller as instructed.
See WARNINGS “To avoid
unintentionally starting...” and “After disconnecting the batteries, wait 90 seconds...” in General
Warnings on page 1-1.
2.
Disconnect wires from the S1 and S2 terminals on the motor using two wrenches to prevent posts from turning.
Set a multimeter to 200 ohms and place the red (+) probe on the S1 terminal and the black (–) probe on the
S2 terminal. The multimeter should indicate continuity. If the reading is incorrect, a possible open field coil or
bad connections at the terminals may be the cause. The motor will need to be removed from the vehicle and
repaired by a qualified technician.
See Motor Removal on page 18-3.
3.
If reading is correct, reconnect the motor wires.
See Motor Installation on page 18-14.
4.
Place the Tow/Run switch in the TOW position and connect the batteries, positive (+) cable first. Tighten battery
terminals to 110 in-lb (12.4 N·m) and coat terminals with Battery Terminal Protector Spray (CCI P/N 1014305) to
minimize corrosion.
Page 18-2
2009 Electric Precedent Maintenance and Service Manual