95hatchH2B

ok heres the story we got a 92 four door with a obd2 d16y8. it was running good then we drove from philadelphia,pa to newark,de and when we got there the coolant temp gauge read super hot, we left the car so it could cool down and when we came back i put the key in and it still read really hot and didnt want to start. it fried the engine harness. so we got the new harness plugged it in and still nothing. and its still read super hot please help me