alternator only charging part time


Oct 16, 2007
my alternator only seems to be charging once in a while according to my scanmaster. i took it off and had autozone check it and they said its fine. After driving around awhile my battery started dropping volts again,down to 10.9 then it might go to 14 for awhile. It has a new NAPA battery. Does this have to be the alternator or could it be something else?
Sound like the typical connection problem in the instument cluster, try tapping your dash while running and see if it changes the charging volts. Very common.

no charge

I agree. It is common for the alt. to not charge because the regulator "exciter",better known as the idiot light,isn't working properly. Does the light come on, key on engine off? It's a good possibility.
there is no idiot light on and hitting the top of dash does nothing.I just had a friend hook up his meter while it was running and says 11.2 on the scanmaster and it says the alternator is bad. i will order the caspers field fix in the morning and see if that takes care of it.