Burnt terminals behind switch

Good morning,

That happens from either a bad connection or high current flow. The switch will have to be replaced along with the wire end in the connector to resolve this.

https://www.2carpros.com/articles/how-a-headlight-switch-works

You can go to a part store and see if they have a connector for the switch as well as the switch.

https://www.2carpros.com/articles/how-to-check-wiring

Roy

Before I replaced the switch none of my lights were working, now that I replaced the switch the running lights work but there a burnt-out connection on the back of the wiring harness that I believe has to be the head lights. What do I need to do to fix the connection if it's burnt out?

The end of the wire or the wire itself will need to be replaced.

Did you check for power coming out of the switch?

Roy