Suzuki: 87 suzuki samurai, voltage drop test, alternator belt

Question
My samurai dies sometimes.  It will not charge the battery.  I put in a new battery and it's dead too.  I can jump it but it won't hold a charge and it won't stay running unless I'm reving it up.  I tested the alternator and it's good.  Any ideas would be greatly appreciated.

Answer
Do a voltage drop test.  This is done by taking a voltmeter (even a cheap one will do)and setting it on the 12 volt scale. now measure the voltage between the block and the negative POST (not the connector on the battery cable) of the battery while cranking the engine You should read significantly less than 2.0 volts.  Do the same between the output terminal of the alternator and the positive post of the battery.  It's also easily possible that the alternator belt can be badly worn, loose  and glazed, and slipping, and not be making any squealing noises.  This too will cause failure to charge.
If you encounter any high voltage on the voltage drop tests, try substituting (or adding) an 8 gauge cable from the block or alternator, and the appropriate post.  Having poor connections, and high resistance in these circuits is not at all uncommon in older vehicles.
scotty