Guardian 4389 Repair Manual page 117

DC CONTROL
4. Connect one test lead to Connector C2 Pin Location 1
(Wire 77). Connect the other test lead to the end of Wire
77 which was previously removed from the BCR. CON-
TINUITY should be measured.
5. Connect one test lead to Connector C2 Pin Location 2
(Wire 66). Connect the other test lead to the end of Wire
66 which was previously removed from the BCR. CON-
TINUITY should be measured.
RESULTS:
If CONTINUITY was not measured in Step 4 or Step
5, repair or replace defective wiring between
Connector C2 and the battery charge relay.
TEST 69 - CHECK BATTERY CHARGER
WIRING
DISCUSSION:
The three pin connector on the battery charger con-
nects the charger to ground and to battery power.
PROCEDURE:
1. Set the AUTO-OFF-MANUAL switch to OFF.
2. Disconnect the three pin connector from the battery
charger.
3. Set a VOM to measure resistance.
4. Connect one meter test lead to Wire 13A at the three pin
connector. Connect the other test lead to Wire 13A at
Fuse F2. CONTINUITY should be measured.
5. Connect one meter test lead to Wire 0 at the three pin
connector. Connect the other test lead to the ground ter-
minal. CONTINUITY should be measured.
RESULTS:
1. If CONTINUITY was NOT measured in Step 4, repair
or replace Wire 13A between the battery charger and
fuse F2.
2. If CONTINUITY was NOT measured in Step 5, repair or
replace Wire 0 between the battery charger and frame
ground.
TEST 70 - CHECK ENGINE RUN WINDING
DISCUSSION:
The engine run winding provides an AC input through
Wire 66A to the circuit board. This input is used for
overspeed sensing. If the input is not received by the
circuit board, immediate shutdown will occur.
PROCEDURE:
1. Set the AUTO-OFF-MANUAL switch to OFF.
PART 4
2. Set a VOM to measure resistance.
3. Disconnect Connector C2 from the side of the control
panel.
4. Disconnect Connector J1 from the circuit board.
5. Connect one meter test lead to Connector C2 Pin
Location 3 (Wire 66A). Connect the other test lead to
Connector J1 Pin Location 8 (Wire 66A). CONTINUITY
should be measured.
6. Connect one test lead to Connector C2 Pin Location 4
(Wire 55). Connect the other test lead to a clean frame
ground. CONTINUITY should be measured.
7. Re-connect connector C2 to the control panel, and re-
connect connector J1 to the circuit board.
8. Set a VOM to measure AC Voltage.
9. Connect the positive meter test lead to Pin Location 8,
Wire 66A of the J1 Connector on the circuit board.
Connect the negative meter test lead to the ground ter-
minal. Set the AUTO-OFF-MANUAL switch to MANUAL.
When the generator starts observe the voltage output
on the VOM. AC voltage should be 8-12 VAC.
10.Set VOM to measure frequency. 62- 63 HZ should be
measured.
RESULTS:
1. If CONTINUITY is not measured in Step 5, repair or
replace Wire 66A between Connector C2 and
Connector J1 at the circuit board.
2. If CONTINUITY was not measured in Step 6, repair or
replace Wire 55 between Connector C2 and the ground
terminal.
3. If CONTINUITY was measured in both Step 5 and Step
6, go to Test 7.
4. If AC voltage is not correct in Step 9, proceed to Test 7.
If frequency is not correct adjust no load frequency and
re-test.
TEST 71 - CHECK N1 AND N2 VOLTAGE
DISCUSSION:
Loss of utility source voltage to the generator will initi-
ate a startup and transfer by the generator. Testing at
the control panel terminal strip will divide the system
in two, thereby reducing troubleshooting time.
PROCEDURE:
Note: Verify that Utility Source Voltage is present.
1. Set the AUTO-OFF-MANUAL switch to OFF.
2. Set a VOM to measure AC voltage.
SECTION 4.4
DIAGNOSTIC TESTS
Page 115