Generac Power Systems 5410, 5412 Test 16 - Check 7.5 Amp Fuse, Test 17 - Check Battery & Cables

Section 7

DIAGNOSTIC TESTS

Test 16 – Check 7.5 Amp Fuse

DISCUSSION:

If the panel-mounted 7.5 amp fuse (F1) has blown, engine cranking will not be possible.

Figure 7-15. – 7.5 Amp Fuse

PROCEDURE:

Push In on fuse holder cap and turn counterclockwise. 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 17.

Test 17 – Check Battery & Cables

DISCUSSION:

If the engine won’t crank or cranks too slowly, the battery may be weak or discharged. See “Battery” on Page 22.

PROCEDURE:

1.Inspect the battery cables and battery posts or terminals for corrosion or tightness. Measure the voltage at the terminal of the starter contac- tor and verify 11-12 volts DC is available to the generator during cranking. If voltage is below 11 volts DC, measure at the battery terminals dur- ing cranking. If battery voltage is below 11 volts DC, recharge/replace battery. If battery voltage is above 11 volts DC, 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 generator and retest.

2.Use a battery hydrometer to test the battery for

(a)state of charge and (b) condition. Follow the hydrometer manufacturer’s instructions carefully.

RESULTS:

1.Clean battery posts and cables as necessary. Make sure battery 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 18.

Test 18 – Check Power Supply to

Printed Circuit Board

DISCUSSION:

If battery voltage is not available to the Printed Circuit Board (PCB), engine cranking and running will not be possible.

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

This test will determine if battery voltage is available to the Printed Circuit Board. Test 20 will check the Start-Stop Switch. Test 21 will check the DC power supply to the Printed Circuit Board’s Wire 56 terminal (J1 Connector, Pin 9).

PROCEDURE:

1.Disconnect J1 Connector from the PCB.

2.On the harness end of the J1 Connector, locate J1, Pin 4 (Wire 15) (see Figure 5-3 on Page 22).

3.Set a VOM to read battery voltage. Connect the meter test leads across Printed Circuit Board Terminal J1, Pin 4 and frame ground. The meter should read battery voltage.

4.Set the VOM to measure resistance (“Rx1” scale). Connect one meter test lead to Wire 0, Pin loca- tion J1-11 on the Printed Circuit Board. Connect the other test lead to a clean frame ground. “Continuity” should be measured.

RESULTS:

1.If battery voltage is NOT indicated in Step 3, check continuity of:

a.Wire 13 between Starter Contactor and Starter Contactor Relay.

b.Wire 13 between Starter Contactor Relay and 7.5 Amp Fuse (F1).

c.Wire 15 to Wire 13 on the 7.5 Amp fuse hold- er (F1).

Repair, reconnect or Replace bad wiring as nec- essary.

2.If battery voltage is indicated but engine will not crank, go to Test 20.

3.If “Continuity” was not measured in Step 4, repair or replace Wire 0 between the Printed Circuit Board and the Ground Terminal.

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