FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Power Transistor Test

NOTE: The circuit tester used in the following test procedures should be of the "analog" type.
1. Disconnect the electrical connector to the Power Transistor.

Power Transistor No. 1 Test:




2. Connect the negative lead of a 1.5 volt battery to terminal # 4 of the power transistor.
3. Connect the positive lead of an ohmmeter to terminal # 13, and the negative lead of the ohmmeter to terminal # 4. There should be NO continuity.
4. Check for continuity when the positive lead of the battery is connected to terminal # 3 of the power transistor. There should be continuity only while the battery is connected.

Power Transistor No. 2 Test:




5. Connect the negative lead of a 1.5 volt battery to terminal # 4 of the power transistor.
6. Connect the positive lead of an ohmmeter to terminal # 12, and the negative lead of the ohmmeter to terminal # 4.
Continuity should NOT exist.
7. Check for continuity when the positive lead of the battery is connected to terminal # 2 of the power transistor. Continuity should exist, while the battery is connected.

Power Transistor No. 3 Test:




8. Connect the negative lead of a 1.5 volt battery to terminal # 4 of the power transistor.
9. Connect the positive lead of an ohmmeter to terminal # 11, and the negative lead of the ohmmeter to terminal # 4. There should be NO continuity.
10. Check for continuity when the positive lead of the battery is connected to terminal # 1 of the power transistor. There should be continuity only while the battery is connected.
Replace the power transistor if there is a deviation in the test results.