new gauge cluster now wont start

If ALL you did was change the cluster, there's nothing in there except for the ammeter that would affect the problem. If you have dome, headlights, other power, the ammeter is hooked up.

Did you have the column connector unhooked? Is it possible it's not seated correctly?

From your description it sounds like a problem unrelated to the cluster, and if the ignition is hot with key off it really sounds like a bad IGN switch

What else did you do?