Generac Power Systems 65, 55, 75 manual TEST 20- CHECK FUEL PUMP, 13.- The LPG Fuel Solenoid FS

Section 7

DIAGNOSTIC TESTS

Figure 7-13. – The LPG Fuel Solenoid (FS)

RESULTS:

1.If battery voltage is not indicated in Step 2, check Wire 15 between the Primer Switch and the 7.5 amp fuse for an open condition.

2.If battery voltage is indicated in Step 2 but not in Step 4, replace the Primer Switch. If battery voltage is NOT indicated in Step 3 repair or replace Wire 14 between the 4-tab Terminal Connector (TC) and the Fuel Primer Switch (SW2).

3.If battery voltage was indicated in Step 4 but not in Step 5:

a.For gasoline models repair or replace Wire 14A between the Primer Switch (SW2) and Fuel Pump Connector 2.

b.For LPG models repair or replace Wire 14A between the Fuel Prime Switch (SW2) and the LPG Fuel Solenoid (FS).

4.If the meter reads anything other than “Continuity” in Step 7, replace the Primer Switch.

5.If the Primer Switch checks good, go to Test 20 for Gasoline models. For LPG models, go to Test 42.

TEST 20- CHECK FUEL PUMP

DISCUSSION:

An inoperative Fuel Pump will (a) prevent the priming function from working and (b) prevent the engine from starting.

PROCEDURE:

1.Remove Fuel Filter and verify that filter is not clogged. Replace filter if necessary.

2.Verify that fuel is available to Fuel Filter inlet. Use an alterna- tive fuel supply if questionable.

3.Remove air filter access panel and air filter. Remove fuel hose from pump. Place a suitable container to catch fuel from fuel pump line. Activate fuel primer switch. Pump should operate and fuel should flow. If pump does not operate, proceed to Step 4.

4.In Test 19, Battery Voltage was checked at Connector 2. This step will test the ground wire. Disconnect Connector 2 at the Fuel Pump. Set the VOM to measure resistance. Connect one test lead to Wire 0, (Pin 1 of Connector 2) that goes to the Control Panel (see Figure 7-12). Connect the other test lead to a clean frame ground . “Continuity” should be measured.

5.To test for an open fuel pump coil, connect one test lead to the Red Wire (Pin 2 of Connector 2) going to the fuel pump. Connect the other test lead to the Black Wire (Pin 1 of Connector 2) going to the Fuel Pump (see Figure 7-15). The VOM should indicate Fuel Pump coil resistance of about 29.5 kW. (Current draw of the pump at nominal voltage is approxi- mately 1.4 amperes MAXIMUM).

Short to Ground:

6.To test for a shorted fuel pump coil, connect one test lead to the Red Wire (Pin 2 of Connector 2, see Figure 7-15). Connect the other test lead to the fuel pump housing. “Infinity” should be measured.

Figure 7-14. – Electric Fuel Pump

RESULTS:

1.If “Continuity” was not measured in Step 4, repair or replace Wire 0 between Connector 2 and the ground terminal.

2.If “Continuity” is measured in Step 4, but pump does not oper- ate in Step 3, replace the Fuel Pump.

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