98 Cadillac Eldorado, replaced alternator now headlights wont work

Just recently replaced the alternator on the Eldorado which was a task, now it runs fine but the headlights wont work. I have checked the fuses and all fine, checked battery connections and reconnected alternator. Still no lights, the day running lights are on the turn signals are on the parking lights or on, but no headlights or high beams. When you put it in drive the day running lights come on, then when you hit the lights on the day running lights turn off and nothing. I need help here I dont know where to go next.