Hello, not sure if this is the right spot, but I recently installed a new radiator for my car. For some odd reason the fans do not turn on automatically when they are suppose to, but if i turn on the heater,ac the fans turn on, but when i turn that off they dont turn back on.. Any advice or idea to the problem? I connected everything like before..

why did you replace the radiator in the first place?

sounds like a thermostat problem

I replaced it because my last one cracked and started to overheat my car. What makes you say it is the thermostat?

did you do anything at all to the thermostat when you were changing the radiator? usually they have a temp sensor that tells the radiator fan when it needs to come on/go off.

I did not touch the thermostat at all. I was youtubing what could be the problem, and came across a coolant sensor might be the problem maybe? I have a feeling it is a sensor but not entirely sure.

run your car idol and watch the temp... once it gets up to about 190, it should kick on... if it does, everything is fine

If the fans don't kick on at the above mentioned point, thermostats are easy to replace and extremely cheap. Your local auto store should always have them in stock.