Midtronics MDX-300 Series, Instruction Manual, Page: 6 / 21

•
6
•
MDX-300 Series
Preparations Before the Test
Before connecting the tester, clean the battery posts or side terminals with
a wire brush and a mixture of baking soda and water. When testing side-
post batteries, install and tighten lead terminal adapters.
IMPORTANT: Do not test at steel bolts. Failure to install terminal adapters
or installing terminal adapters that are worn or dirty may result in inac-
curate test results. To avoid damage, never use a wrench to tighten the
adapters more than 1/4 turn.
If you are testing in the vehicle, make sure all accessory loads are off, the
key is not in the ignition, and the doors are closed. If the vehicle was run-
ning before the test, turn on the headlights to remove the battery’s surface
charge. Let the battery rest for at least 1 minute to recover before testing.
Connecting the Tester
• Connect the red clamp to the positive (+) terminal and the black
clamp to the negative (–) terminal.
• For a proper connection, rock the clamps back and forth. The tester
requires that both sides of each clamp be firmly connected before
testing. A poor connection will produce a CHECK CONNECTION
or WIGGLE CLAMPS message. If the message appears, clean the
terminals and reconnect the clamps.
• The preferred test position is at the battery terminals. If the battery is
not accessible, you may test at the jumper post; however, the avail-
able power measurement may be lower than the actual value.
Battery Test
When you first connect the tester to the battery, it functions as a voltmeter
until you press the ENTER button to start the test.
After you press ENTER , scroll to each parameter using the UP or DOWN
ARROW button and press ENTER to select. If any messages appear dur-
ing the test, see “Test Messages” on page 11.