Guardian Technologies 5308, 4582 & 4987, 4451 & 4986 Test 23 Check Voltage at Starter Contactor SC

Section 6

DIAGNOSTIC TESTS

measure at the battery terminals during cranking. If battery voltage is below 11 volts DC, recharge/replace battery. If bat- tery 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 bat- tery 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, refer back to Flow Charts.

TEST 23 - Check Voltage at Starter

Contactor (SC)

PROCEDURE:

1.Set voltmeter to measure DC voltage.

2.Disconnect Wire 16 from the Starter Contactor located on the Starter motor.

3.Connect the positive meter test lead to Wire 16 previous- ly removed. Connect the negative meter test lead to frame Ground.

4.Place the Start-Run-Stop Switch to Start. 12 VDC should be measured.

5.Reconnect Wire 16 to the Starter Motor.

RESULTS:

Refer back to flow chart.

Test 24 - Check Starter Contactor (SC)

PROCEDURE:

1.Carefully inspect the starter motor cable that runs from the Battery to the Starter Motor. Cable connections should be clean and tight. If connections are dirty or corroded, remove cable and clean cable terminals and studs. Replace any cable that is defective or badly corroded. Set the voltmeter to mea- sure DC voltage. Connect the positive (+) meter test lead to the Starter Contactor stud that the battery cable is connected to. Connect the negative (-) meter test lead to a clean frame ground. Battery voltage should be measured (see Figure 6-28,

STEP 1 TEST POINT).

	STARTER	16
	SWITCH	50
BATTERY	30
12V

CONNECTING

DIAGRAM

	PERMANENT MAGNET
STARTER	step 1
	TEST POINT
CONTACTOR
	step 2
	TEST POINT
STARTER
MOTOR

Figure 6-28. – The Starter Contactor (SC)

2.Set the voltmeter to measure DC voltage. Connect the positive

(+)meter test lead to the Starter Contactor stud that has the small jumper wire connected to the Starter. Connect the nega- tive (-) meter test lead to a clean frame ground. Set the Start- Stop Switch to Start. Battery voltage should be measured (see Figure 6-28, STEP 2 TEST POINT).

RESULTS:

1. If battery voltage was not measured in Step 1, repeat Test 22.

2If battery voltage was measured in Step 1, but not in Step 2, replace the Starter Contactor.

4.If battery voltage was measured in Step 2 but the engine still does not crank, refer back to the Flow Chart.

Test 25 - Check Starter Motor

Conditions Affecting Starter Motor Performance:

1.A binding or seizing condition in the Starter Motor bearings.

2.A shorted, open or grounded armature.

a.Shorted, armature (wire insulation worn and wires touching one another). Will be indicated by low or no RPM.

b.Open armature (wire broken) will be indicated by low or no RPM and excessive current draw.

c.Grounded armature (wire insulation worn and wire touching armature lamination or shaft). Will be indicated by excessive current draw or no RPM.

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