800.MACTOOLS
47
Meter setup to measure alternator output voltage:
•
Set the rotary switch to voltage ( ) setting.
•
Press the “
DC/AC
” button until “ ” appears on the display.
•
Insert the black lead in the “
COM
” jack.
•
Insert the red lead in the “
” jack.
Turn all vehicle accessories off.
Connect:
•
Black lead to the negative (-) battery post.
•
Red lead to the positive (+) battery post.
Press the “
REC
” button (selects the MAX.MIN.AVG function).
Start the engine and run it at 2,000 RPMs. A reading of 13.5V to 15.5V is an acceptable charging rate.
If the voltage is low, check for:
•
Defective alternator or regulator (see tests that follow)
•
Cracked, glazed, or loose drive belt
•
Faulty or loose wires or connectors
Alternator Output (+) Voltage Test (Loaded)
This test is necessary only if the vehicle failed the previous test.
Red
Black
12V Battery
Alternator Output
(by-passed regulator)
