Feed Circuit Test

The starter feed circuit test (voltage drop method) will determine if there is excessive resistance in the high-amperage feed circuit. For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS . (Refer to ELECTRICAL/WIRING DIAGRAM INFORMATION - DESCRIPTION) .

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

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

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

1. Battery is fully-charged and load-tested. Refer to Battery  for the procedures. (Refer to ELECTRICAL/BATTERY SYSTEM/BATTERY - DIAGNOSIS AND TESTING) .
2. Fully engage the parking brake.
3. Place the automatic transmission gearshift selector lever in the Park position or place the manual transmission gearshift selector in the Neutral position.
4. Verify that all lamps and accessories are turned off.
5. Prevent the engine from starting.

Fig 1: Connecting Positive Lead Of Voltmeter To Battery Negative Terminal Post

Courtesy of DAIMLERCHRYSLER CORP.

1. Connect the positive lead of the voltmeter (1) to the battery (2) negative terminal post. Connect the negative lead of the voltmeter (1) to the battery (2) negative cable clamp. Rotate and hold the ignition switch in the Start position. Observe the voltmeter. If voltage is detected, correct the poor contact between the cable clamp and the terminal post.
   Fig 2: Connecting Positive Lead Of Voltmeter To Battery Positive Terminal Post

   Courtesy of DAIMLERCHRYSLER CORP.
2. Connect the positive lead of the voltmeter (1) to the battery (2) positive terminal post. Connect the negative lead of the voltmeter (1) to the battery (2) positive cable clamp. Rotate and hold the ignition switch in the Start position. Observe the voltmeter. If voltage is detected, correct the poor contact between the cable clamp and the terminal post.
   Fig 3: Connecting Voltmeter Between Battery Positive Cable & Starter Solenoid B (+) Terminal Stud

   Courtesy of DAIMLERCHRYSLER CORP.
3. Connect the voltmeter (2) to measure between the battery (1) positive terminal post and the starter (3) solenoid battery terminal stud. Rotate and hold the ignition switch in the Start position. Observe the voltmeter. If the reading is above 0.2 volt, clean and tighten the battery cable connection at the solenoid. Repeat the test. If the reading is still above 0.2 volt, replace the faulty battery positive cable.
   Fig 4: Connecting Voltmeter Between Negative Battery Cable & Good Clean Ground On Engine Block

   Courtesy of DAIMLERCHRYSLER CORP.
4. Connect the voltmeter (1) to measure between the battery (2) negative terminal post and a good clean ground on the engine block (3). Rotate and hold the ignition switch in the Start position. Observe the voltmeter. If the reading is above 0.2 volt, clean and tighten the battery negative cable attachment on the engine block. Repeat the test. If the reading is still above 0.2 volt, replace the faulty battery negative cable.
   Fig 5: Connecting Positive Lead Of Voltmeter To Starter Housing

   Courtesy of DAIMLERCHRYSLER CORP.
5. Connect the positive lead of the voltmeter (3) to the starter (1) housing. Connect the negative lead of the voltmeter to the battery (2) negative terminal post. Rotate and hold the ignition switch in the Start position. Observe the voltmeter. If the reading is above 0.2 volt, correct the poor starter to engine block ground contact.

If the resistance tests detect no feed circuit problems, refer to Starter Motor  . (Refer to ELECTRICAL/STARTING/STARTER MOTOR - DIAGNOSIS AND TESTING) .