Generac Power Systems 5411, 5412 Test 22 - Check Starter Contactor Relay, 18. - Test 20, Step

Section 7

DIAGNOSTIC TESTS

0000

CONTINUITY

87

14

25

36

DEPRESSED

AWAY FROM

TERMINAL BEING

TESTED

5.Connect the VOM positive (+) test lead to Wire 56 (Pin Location J1-9) at the Printed Circuit Board. Connect the other test lead to frame ground.

6.Actuate the Start-Stop Switch to the “START” position. The meter should indicate battery volt- age.

RESULTS:

1.If battery voltage was measured in Step 6, but not in Step 4, repair or replace Wire 56 between the Printed Circuit Board and Starter Contactor Relay.

2.If battery voltage was not available in Step 6, replace the Printed Circuit Board.

3.If battery voltage is available in Step 4 but engine does not crank, go to Test 22.

Test 22 – Check Starter Contactor

Relay

Figure 7-18. – Test 20, Step 6

RESULTS:

1.If “Continuity” is not measured in Step 3, repair, reconnect or replace Wire 0 (between Start-Stop Switch and ground terminal) as necessary.

2.If the Start-Stop Switch (SW1) failed any part of Steps 2 or 3, replace the switch.

5. If switch tests GOOD, go to Test 21.

Test 21 – Check Power Supply to

Wire 56

DISCUSSION:

If battery voltage is available to the Printed Circuit Board in Test 18, then DC voltage should be deliv- ered to Wire 56 when the Start-Stop Switch is set to “START” (Test 20). This test will check to see if the Printed Circuit Board is delivering battery voltage to the Wire 56 terminal.

PROCEDURE:

1.Set a VOM to measure DC voltage (12 VDC).

2.Disconnect Wire 56 from its Starter Contactor Relay terminal.

3.Connect the meter positive (+) test lead to the disconnected end of Wire 56. Connect the other test lead to frame ground. No voltage should be indicated.

4.Actuate the Start-Stop Switch to its “START” posi- tion. The meter should indicate battery voltage. If battery voltage is present, stop the procedure.

DISCUSSION:

If battery voltage is available to Wire 56 but the engine won’t crank, the possible cause could be a failed Starter Contactor Relay.

1316

13	16
COM	NO

56 56 0

0

Figure 7-19. – Starter Contactor Relay

PROCEDURE:

1.Set the VOM to measure resistance (“R x 1” scale). Remove Wire 0 from the Starter Contactor Relay (SCR). Connect one meter test lead to Wire 0, and connect the other meter test lead to frame ground. “Continuity” should be measured. Reconnect Wire 0.

2.Set the VOM to measure resistance (“R x 1” scale). Disconnect Wire 16 and Wire 13 (Wire 13 is 12 VDC isolate from ground) from the Starter Contactor Relay (SCR). Connect one meter test lead to an SCR terminal, and connect the other meter test lead to the remaining SCR terminal.

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