Guardian Technologies 4270 manual TEST 22- CHECK BATTERY & CABLES, TEST 21- CHECK 14 AMP FUSE

Section 7

DIAGNOSTIC TESTS

PROCEDURE:

1. Set a VOM to measure DC voltage.

TEST 22- CHECK BATTERY & CABLES

2.Disconnect the connector from the wires of the fuel pump.

3.Place the positive (+) test lead on Wire 14 and the negative (-) test lead to clean ground. Press the pre-heat switch, battery voltage should be measured, if not, disconnect the other end of Wire 14. Place test leads on each end of Wire 14. Set a VOM to measure continuity. Continuity should be measured.

4.Disconnect Wire 0 from the black wire of the fuel pump. Place one test lead on Wire 0 and the other test lead to ground. Continuity should be measured. If continuity is not measured, replace Wire 0.

5.Jump 12 VDC to white wire of fuel pump, and jump black wire to clean frame ground. Fuel pump should pump.

RESULTS:

1.If battery voltage and continuity are not measured in step 3, then replace bad wire.

2.If pump does not pump in step 5, replace the pump

TEST 21- CHECK 14 AMP FUSE

DISCUSSION:

If the panel-mounted 14 amp fuse (F1) has blown, engine cranking will not be possible.

DISCUSSION:

If the engine won't crank or cranks too slowly, the bat- tery may be weak or discharged. See “Battery” on Page 24.

PROCEDURE:

1.Inspect the battery cables and battery posts or terminals for corrosion or tightness. Measure the voltage at the terminal of the starter contactor and verify 11-12 VDC is available to the generator during cranking. If voltage is below 11 VDC, mea- sure at the battery terminals during cranking. If battery voltage is below 11 VDC, recharge/replace battery. If battery voltage is above 11 VDC, check for proper battery cable sizing (see “BATTERY CABLES” on Page 24). If battery or cables are still suspected, connect an alternate battery and cables to the gen- erator and retest.

2.Use a battery hydrometer to test the battery for (a) state of charge and (b) condition. Follow the hydrometer manufactur- er's instructions carefully.

RESULTS:

1.Clean battery posts and cables as necessary. Make sure bat- tery cables are tight.

2.Recharge the battery, if necessary.

3.Replace the battery, if necessary.

4.If battery is good, but engine will not crank, go to Test 23.

Figure 7-11. – 14 Amp Fuse

PROCEDURE:

Push in on fuse holder cap and turn counterclock- wise. Then, remove the cap with fuse. Inspect the Fuse.

RESULTS:

If the Fuse element has melted open, replace the Fuse with an identical size fuse. If Fuse is good, go to Test 22.

TEST 23- CHECK POWER SUPPLY TO

CIRCUIT BOARD

DISCUSSION:

If battery voltage is not available to the circuit board, engine cranking and running will not be possible.

If battery voltage is available to the board, but no DC output is delivered to the board's Wire 56 terminal while attempting to crank, either the circuit board is defective or the Start-Stop Switch has failed.

This test will determine if battery voltage is available to the Engine Controller circuit board. Test 24 will check the Start-Stop Switch. Test 25 will check the DC power supply to the circuit board's Wire 56 termi- nal (Receptacle J1, Pin 1).

PROCEDURE:

1.On the Engine Controller Circuit Board, locate Terminal 1 to which Wire 15 connects (see chart on Page 24).

2.Set a VOM to read battery voltage. Connect the meter test leads across circuit board Terminal 1 and ground. The meter should read battery voltage.

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