I have a problem on hatch.. hopefully someone can cure this. My temp gauge goes up once in a while and i notice that my fan doesn't turn on when this occur. I tested the fan and it's working fine. I believe it's the temp switch behind the block. I bought one today and I'm going to put them on this weekend. The main issue is I notice when my temp goes up driving at night and my headlights are on.. If I turn the headlights off the temp gauge goes down! could this be the temp switch or could it be something else?

 

Sounds like an Electrical problem. Maybe a bad ground. I had a friend whos temp gauge went up with he turned on his light.... = bad ground strap at battery

 

sounds like a ground strap or a loose connection at your temp sending unit. Make sure your ground stap is SECURE and the bolt isn't stripped.