Join Date: Aug 2006
Location: Arlington, VA
Thanked 14 Times in 12 Posts
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Before you pull off the alternator, it would really be wise to:
1. check that ALL connections and ALL connectors are clean and tight;
2. ensure that the belt to the alternator is properly tensioned;
3. measure the voltage at the battery while the engine is running.
What size wire do you have from the alternator positive terminal to the battery. Does it go to the starter solenoid? To the 1-2-OFF switch? To the battery directly? Which battery?
Be especially careful to check the ground connections. If the alternator doesn't have its own negative cable to the battery, it should have. Often, connection to the engine alone presents too much resistance in the circuit for proper charging.
Also, if you haven't used the Harbor Freight clamp-on ammeter before, try to find a DC circuit where you can verify its proper operation. It should be on the DC range, and clamped around ONLY ONE wire in a pair, not both.
I'd do these things before pulling off the alternator; it could be just fine.