Guardian Technologies 4758 Test 52 Test Fuel Solenoid, Test 53 Check Circuit Board Wire Output

SECTION 4.4

DIAGNOSTIC TESTS

PART 4

DC CONTROL

TEST 52 - TEST FUEL SOLENOID

Note: This test is for fuel regulators equipped with idle circuit port only. See Figure 16. These units have an additional 1/4” fuel hose.

DISCUSSION:

When the Fuel Solenoid (FS) is energized, gas pressure is available internally to the on demand Fuel Regulator. Gas pressure will then be available to the idle circuit port of the Fuel Regulator.

3.While observing the meter, set the AUTO-OFF-MANUAL switch to MANUAL.

a.The circuit board’s crank and run relays should energize and the engine should crank and start.

b.The meter should indicate battery voltage.

c.If battery voltage is indicated, proceed to Step 4. If battery voltage is NOT indicated, proceed to Test 53 results.

4.Disconnect Wire 14 at the Fuel Solenoid (FS).

PROCEDURE:

1.Disconnect Wire 56 from the starter contactor relay (SCR). This will disable the unit from cranking. For single cylinder units, disconnect from the starter contactor (SC) and isolate it from ground.

2.Remove the fuel hose from the idle circuit port barbed fitting.

3.Attach a manometer (Generac P/N 0C7977) to the idle circuit port barbed fitting.

4.Set the AUTO-OFF-MANUAL switch to MANUAL. The engine will not crank, but gas pressure should be observed on the manometer at 11”-14” of water column.

5.Set the AUTO-OFF-MANUAL switch to OFF. Remove the manometer. Re-attach the fuel hose to the idle circuit port barbed fitting. Re-connect Wire 56 to the starter contactor relay or starter contactor.

RESULTS:

1.If gas pressure was measured, proceed to Test 55.

2.If gas pressure was NOT measured, replace the fuel solenoid (FS).

TEST 53 - CHECK CIRCUIT BOARD WIRE 14

OUTPUT

DISCUSSION:

During any cranking action, the circuit board’s crank relay (K1) and run relay (K2) both energize simultaneously. When the run relay energizes, its contacts close and 12 volts DC is delivered to Wire 14 and to a fuel solenoid. The solenoid energizes open to allow fuel flow to the engine. This test will determine if the circuit board is working properly.

PROCEDURE:

1.Set the AUTO-OFF-MANUAL switch to OFF.

2.Connect the positive (+) test lead of a DC voltmeter (or VOM) into Pin 7 (Wire 14) of the circuit board connector J1. Connect the common (-) test lead to frame ground.

a. Connect the positive (+) test lead to Wire 14. Connect the negative test lead to a clean frame ground. Set the AUTO-OFF-MANUAL switch to MANUAL. Battery voltage should be measured. If battery voltage is indicated, proceed to Step 5.

b. Connect the positive (+) test lead to Wire 14 at the 4-tab terminal block in the control panel, see Figure 17. Connect the negative (-) test lead to frame ground. While observing the meter, set the AUTO-OFF-MANUAL switch to MANUAL. Battery voltage should be measured.

Figure 17. 4-Tab Terminal Block

5.Set the VOM to it’s “R x 1” scale.

6.Disconnect Wire 0 from the Fuel Solenoid (FS). Connect one test lead to Wire 0 and the other test lead to a clean frame ground. CONTINUITY should be measured.

RESULTS:

1.If the engine cranks but does not start and battery voltage was NOT measured in Step 3, replace the circuit board.

2.If the engine cranks and battery voltage was measured in Step 3, but there was no battery voltage in Step 4(a), repair or replace Wire 14 between 4-tab terminal block and the Fuel Solenoid (FS).

3.If the engine cranks and battery voltage was measured in step 3 and no battery voltage is measured in step 4b, repair or replace Wire 14 between the J1 connector on the circuit board and the 4-tab terminal block.

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