Inspect harness in those area's it burned your heating element wire is what that is........Ohm test heat element should be 50 ohms or less typically then replaced the thermal cut offs on your element housing and replace the operating thermostat near the blower housing. Cut back any wires that are burnt and buttsplice extension pieces as needed............Check for voltage after you're done and it's up and running the element should have 240v if you have more you have issues.