Hey guys, im lost on this problem so I've come here looking for help. My girlfriend has a 99 civic dx and it overheats. The person her uncle (who she bought it from) bought it from were some 16-17 year old kids trying to rice it up. The radiator fan is hotwired to the battery and the temp switch is missing.

Let me clarify; the temp switch is bolted in next to the thermostat, but theres not a connector to plug it in. I'm suspecting this is the problem. when it overheats, the car is pushing the fluid back into the front. It has popped hoses off and now it tries to shoot the fluid through the top of the overflow tank. What is my best bet here? Should I try to cut a connector from a salavage yard and wire it in? I'm not sure where to wire it in the harness. Could use some insight here.

 

That is the fan switch... it would turn the cooling fan on when the fluid in the thermostat housing reaches a certain temperature. Since you have the fan running all of the time, and the car still isn't cooling, your issue is NOT the fan switch. You unfortunately have a blown head gasket and this is why you are pushing coolant out of the over flow tank and blowing hoses off. You will need to repair the head gasket issue first... then correct the fan switch wiring before you go driving again.