1990 Chevy astro van charging system test how do I use a volt meter ac dc 10 50amp ?
Turn it to DC put the red side to the positive lug on the alternator and the black to a ground like the battery - post.
The battery with the engine off should read a little more than 12 volts. Start the engine and it should read a little more than 14 volts. You can test from the battery posts to avoid getting a test lead caught in the belt.
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