Charging system not working

[neanderthal@ardvark.com]

     Steve,
           My experience has been that when the alternator quits charging, it has 
always been the brushes, and the mileage on your car is about right for the 
brushes to be worn out.  It is relatively easy to replace brushes (I have replaced
about five or six sets) but you may have to do some calling around to find an
auto parts store that carries brushes. Look in the yellow pages under auto
electric.  Typically the cost for brushes is under $5.00.   If I remember correctly,
 you don't have to remove the alternator to replace the brushes on a 5000. 
The brushes and the regulator are a module that screws (two screws) onto
 the back of the alternator.  From the symptoms you describe, I don't think
 that the battery is bad because when you charge it, it holds a charge for a 
while.  Normal system voltage when the alternator is running should be
around 14 vdc. Without the alternator, the voltage would be about 12 vdc
or so, depending on load.

                                            Good luck,
                                            Mike Loeks
                                            86 5kcstq  Squared
                                            84 Landcruiser Wagon (for sale)