put in a new battery and the only thing that gets power is the head lights. Any ideas what to look for?
Check the main fuse,and ecm fuse.
If you put the battery in backwards or arched it, that is the only thing that will work is the lights, do what T S T stated, you most likely blew all of the critical mains.
Main fuse / fusable link located under the hood.
Looking for a Used MX-5 Miata in your area?
CarGurus has 4,225 nationwide MX-5 Miata listings starting at $2,995.
Search Mazda MX-5 Miata Questions
Mazda MX-5 Miata Experts