ALtenator

i have a 1994 ford explorer and i think the altenator is bad. someone told i can check w/ a screwdriver how do i do that?

What's the symptoms?

You're heading for problems if you take that advice. And do not remove one of the battery connecttions to see if the engine still runs. Good digital voltmeters are less than $10 and you can't effectivly diagnose problems without one.