i hada back feed during boosting and now my alternator wont pass current,

Possible damage to PCM-Regulated by that.Check ALL wiring and connectors. 3.3L engine? Check harness down in drivers side inner fender area corrosion in plug can cause problems.

Possible issue with the computer, that is what regulates the charging of the alternator. If so a external regulator can be installed by a professional that knows how to do it, cheaper then a computer.