1989 Chevrolet Van - Alternator

The alternator in my van doesn’t work but when it idles down at works it’s charged is my battery little bit what would be the problem

That’s probably the solution. Check and clean both ends of both battery cables. If that doesn’t work, check voltage at battery while idling and at higher rpms. You should see 14.2 - 14.6 volts. If not, replace alternator.

Let me guess . . .

You’ve got about 13V at idle with no lights, ac or radio on

And you’ve probably got only 12V at idle with lights, ac and radio on

If so . . . you need a new alternator