Generac Power Systems 5412 Test 19 - Check Continuity of Wire, Test 20 - Check Start-Stop Switch

Section 7

DIAGNOSTIC TESTS

Test 19 – Check Continuity of Wire 17

DISCUSSION:

A faulty condition in Wire 17 could prevent the unit from cranking when the Start-Stop switch is held in

the “Start” position.

PROCEDURE:

1.Disconnect Wire 17 from its Switch terminal and connect it to frame ground. The engine should crank. If unit cranks, proceed to Step 2. If unit does not crank when grounding Wire 17, go back to Test 18 “Check Power Supply to Printed Circuit Board”, then repeat Step 1. If unit cranks, proceed to Test 20.

2.With Wire 17 still disconnected from SW1, discon- nect the J1 Connector from the PCB.

3.Set a VOM to its “Rx1” scale and zero the meter.

4.Connect one meter test lead to each end of Wire 17.

712

712

JUMPER WIRE

18	8	7	0
	1	4

25

18

36

0

17	LED
	712	0
		18
	START 17	STOP
	PRIME
		SW1
	0	0
	0

5. “Continuity” should be measured.

RESULTS:

Figure 7-16. – Start-Stop Switch

1.If “Continuity” is not measured in Step 5, repair or replace Wire 17.

2.If “Continuity” is measured in Step 5, replace PCB.

Test 20 – Check Start-Stop Switch

DISCUSSION:

Engine cranking and startup is initiated when Wire 17 from the Printed Circuit Board (PCB) is connected to frame ground by setting the Start-Stop Switch to “START”.

Engine shutdown occurs when Wire 18 from the PCB is connected to frame ground by the Start-Stop Switch.

A defective Start-Stop Switch can result in (a) failure to crank when the switch is set to “START”, and/or (b) failure to shut down when the switch is set to “STOP”.

0000

CONTINUITY

87

14

25

36

DEPRESSED

AWAY FROM

TERMINAL BEING

TESTED

PROCEDURE:

Refer to Problem 6 (Section 6).

1.Set a VOM to its “Rx1” scale and zero the meter.

2.Remove the 7.5 amp fuse. Disconnect all wires from Start-Stop Switch (SW1).

3.Inspect the ground Wire 0, between the Start- Stop Switch and the grounding terminal. Connect one meter test lead to Wire 0 on SW1. Connect the other test lead to a clean frame ground. “Continuity” should be measured.

Figure 7-17. – Test 20, Step 5

5.Connect one test lead to the Terminal 1 of SW1 (see Figure 7-17). Connect the other test lead to Terminal 2 of SW1. “Continuity” should be mea- sured.

6.Connect one test lead to the Terminal 2 of SW1 (see Figure 7-18). Connect the other test lead to Terminal 3 of SW1. “Continuity” should be mea- sured.

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