I own a 57 3100 all orginal. My Temp gauge works when it feels like it. Wont work for months then works for a few weekend drives and then nothing again. I have changed the sending unit and felt around for a loose connection. I am not electrically inclined at all and can't figure this one out. My engine is a 235 if that helps. Is it a bad connection? Its gotten to be kind of funny when my daughters get in the cab for a ride. We all check to see if Mr Temp Gauge will work this time! Help please.