1991 dodge ram d150 not charging battery. I had the alternator checked and its good and the wiring looks fine

Did you remove the alternator and have it tested, or was it tested while the vehicle was running? Have you load-tested the battery?

I removed the alternator and had it tested. No I have not load-tested the battery where do I have the battery tested at?

Does jump-starting work? If you're not too far from a parts store, I would drive the truck down there and have them test the alternator while it's in the truck. Sometimes it doesn't give a completely accurate reading if it's not under full load.

You can also have your battery tested at the same place you had the alternator tested. It shouldn't drop down past 10-10.5V while under load.