: 1024x774 px
: June 25, 2018
The test procedure is quite simple. Set the meter to read DC volts, and set the correct range if needed. Some meters will select the correct range automatically. Nearly all meters will come with instructions on how to set them to read DC volts. Next, connect the meter across the vehicle battery, positive (+) to positive (+) and negative (-) to negative (-). With the engine running at a moderate idle - say 1200 to 1500 RPM, the meter should read approximately 13.8 to 14.8 volts and be steady. If the reading is substantially outside these figures and all other items mentioned have been tested and verified good, then the alternator is likely defective.
Seeking the Elusive Electrical Problem. Many times electrical problems are the most elusive, because they can occur intermittently. For example, the car engine may not work properly, but only after the engine warms up. Or the ignition works randomly. Perhaps the engine cuts out without notice while cruising down the highway. Then again, your car might have a faulty alternator or a defective wire.