I have a 86 honda civic,The fan does not turn on when hot. I have changed thermostat, radiator fan switch, the one on the bottom of the radiator! The top hose always gets hot and bottom one always stays cold, overheats and blows out overflow on a 10 minute drive in town. Have power to relay on fender and sensor. ANY advise is appreciated. Need to check radiator also. What else. How do I check water pump. First time honda owner HELP!!!!!!!! Thanks Chuck