Diagnosis And Testing: Testing

VOLTAGE DROP TEST

WARNING: If the battery shows signs of freezing, leaking, loose posts, or low electrolyte level, do not test, assist-boost, or charge. The battery may arc internally and explode. Personal injury and/or vehicle damage may result.

WARNING: Explosive hydrogen gas forms in and around the battery. Do not smoke, use flame, or create sparks near the battery. Personal injury and/or vehicle damage may result.

WARNING: If the battery is equipped with removable cell caps, be certain that each of the cell caps is in place and tight before the battery is returned to service. Personal injury and/or vehicle damage may result from loose or missing cell caps.

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

The battery is fully-charged and tested. See MICRO 530 BATTERY TESTER .
Fully engage the parking brake .
If the vehicle is equipped with an automatic transmission, place the gearshift selector lever in the Park position. If the vehicle is equipped with a manual transmission, place the gearshift selector lever in the Neutral position and block the clutch pedal in the fully depressed position .
Verify that all lamps and accessories are turned off .
To prevent a gasoline engine from starting, remove the Automatic ShutDown (ASD) relay. The ASD relay is located in the Integrated Power Module (IPM), in the engine compartment. See the fuse and relay layout label on the underside of the IPM cover for ASD relay identification and location .

Fig 1: Connecting Positive Lead Of Voltmeter
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Connect the positive lead of the voltmeter (1) to the battery negative terminal post. Connect the negative lead of the voltmeter (1) to the battery negative cable terminal clamp. Rotate and hold the ignition switch in the Start position. Observe the voltmeter. If voltage is detected, correct the poor connection between the battery negative cable terminal clamp and the battery negative terminal post.

Fig 2: Connecting Negative Lead Of Voltmeter

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Connect the positive lead of the voltmeter (1) to the battery positive terminal post. Connect the negative lead of the voltmeter to the battery positive cable terminal clamp. Rotate and hold the ignition switch in the Start position. Observe the voltmeter. If voltage is detected, correct the poor connection between the battery positive cable terminal clamp and the battery positive terminal post.

Fig 3: Connecting Positive Lead Of Voltmeter To Battery Negative Terminal Post
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Connect the voltmeter (2) to measure between the battery positive cable terminal clamp (1) and the starter solenoid (3) B(+) 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 positive cable eyelet terminal connection at the starter solenoid B(+) terminal stud. Repeat the test. If the reading is still above 0.2 volt, replace the faulty battery positive cable.

Fig 4: Measuring Between Battery Negative Cable Terminal Clamp
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Connect the voltmeter (1) to measure between the battery (2) negative cable terminal clamp and a good clean ground (3) on the engine block. 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 eyelet terminal connection to the engine block. Repeat the test. If the reading is still above 0.2 volt, replace the faulty battery negative cable.