Ford Repair: 88 tarus gl 3.0 light flicker, light flicker, headlamp switch

Question
just installed new alternator. but running and tail lights flicker along with head lights

Answer
You haven't given me enough information, for instance did the lights have this problem before you replaced the alternator? Why did you replace the alternator?

I'm thinking you need to check connections, make sure the grounds are tight. Some '80s Taurus had problems with the headlamp switch connector getting hot and melting. Without more details that's all I can offer you.