: 4496x3000 px
: June 20, 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.
Between the electrolyte and the lead plates, a chemical reaction is created. This produces dangerous, explosive gases that vent through the battery cover vents. Because of this, caution should be taken when you charge or jump start a low battery. The same caution should also be taken every time you are working under the hood of your vehicle. It is important to provide as good ventilation as possible in the battery, so always keep it clean.