Feed Circuit Test

The starter feed circuit test (voltage drop method) will determine if there is excessive resistance in high-amperage feed circuit. For complete starter wiring circuit diagrams, refer to appropriate Wiring Diagram.

When performing these tests, it is important to remember that voltage drop is giving an indication of resistance between two points at which voltmeter probes are attached.

>>Example:<< When testing resistance of positive battery cable, touch voltmeter leads to positive battery cable clamp and cable connector at starter solenoid. If you probe positive battery terminal post and cable connector at starter solenoid, you are reading combined voltage drop in positive battery cable clamp-to-terminal post connection and positive battery cable.

The following operation will require a voltmeter accurate to 1/10 (0.10) volt. Before performing tests, be certain that following procedures are accomplished:

• Battery is fully-charged and load-tested.
• Fully engage parking brake.
• Place gearshift selector lever in Park position.
• Verify that all lamps and accessories are turned off.
• To prevent a gasoline engine from starting, remove the automatic shut down relay located in the integrated power module. Refer to label on IPM cover for relay location.

-- Connect positive lead of voltmeter to negative battery cable terminal post. Connect negative lead of voltmeter to negative battery cable clamp. Rotate and hold ignition switch in START position. Observe the voltmeter. If voltage is detected, correct poor contact between cable clamp and terminal post.

• 1 - Voltmeter.
• 2 - Battery.

-- Connect positive lead of voltmeter to positive battery terminal post. Connect negative lead of voltmeter to battery positive cable clamp. Rotate and hold ignition switch in START position. Observe the voltmeter. If voltage is detected, correct poor contact between cable clamp and terminal post.

• 1 - Battery.
• 2 - Voltmeter.
• 3 - Starter motor.

-- Connect voltmeter to measure between battery positive terminal post and starter solenoid battery terminal stud. Refer to Fig 2. Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is more than 0.2 volt, clean and tighten battery cable connection at solenoid. Repeat test. If reading is still more than 0.2 volt, replace faulty positive battery cable.

• 1 - Voltmeter.
• 2 - Battery.
• 3 - Engine ground.

-- Connect voltmeter to measure between negative battery terminal post and a good clean ground on engine block. Refer to Fig 3. Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is more than 0.2 volt, clean and tighten negative battery cable attachment on engine block. Repeat test. If reading is still more than 0.2 volt, replace faulty negative battery cable. >>Note: Certain diesel equipped models use dual batteries. If equipped with dual battery system, this procedure must be performed twice, once for each battery.<<

• 1 - Starter motor.
• 2 - Battery.
• 3 - Voltmeter.

-- Connect positive lead of voltmeter to starter housing. Connect negative lead of voltmeter to negative battery terminal post. Refer to Fig 4. Rotate and hold ignition switch in START position. Observe voltmeter. If reading is more than 0.2 volt, correct poor starter to engine block ground contact.