Radiator fan not comming on

did it get to temperature for the fans to turn on?

Yes nearly over heated at idle and still no fan

Did you bleed all the air out of the system? If you have air in the system, temp sensor cannot work properly and fans will not turn on.

Um no any idea how i do that

Best way is invest in a radiator fill funnel kit, With funnel installed fill with coolant and let engine idle while the air works it's way out keep adding until system will not take anymore,jacking the front end and high as you safely can helps also.keep heat on and fan on high until blows great heat,may need to bring RPM's up during the process.

Thank ill try that

Just be patient it's kind of a tricky deal knowing if you did get all the air out. the heat will tell the truth,if your getting poor heat and temp gauge keeps going up you have air,if the gauge settles and you have great heat your good.

Cjsras is correct and covered it well but nobody mentioned the coolant temperature sensor that tells the fan to come on. When you locate it, ground it on the frame and see if fan comes on. Replace if proven faulty. The second temperature sensor runs the temperature gauge.

Is that the one that is located inline with one of the hoses conected to the radiator

As I said before, the temp sensor cannot work properly with a air bubble surrounding it.

The fan switch is located in the radiator, if it was unplugged it would be running all the time while the key is ON or the motor running, might be worth the $30ish bucks to replace it as its the only thing you haven't tested.

Hello all thanks for the help replaced both the fan and main temp switch now every works.

*two thumbs up*

The cooling fan switch looks just like a coolant temp sensor on a lot of Hondas. I'm workin on a 99 civic LX right now and the cooling fan switch is located on the thermostat housing were u would think the coolant temp sensor goes but the temp sensor is in the head. They look the same when installed but remove them an they are diff. Not all fan switches are on the fan itself and not all are 2 or 3 wire. I've seen Hondas with one wire fan switch. I would replace the temp sensor and fan switch u can get them as a pair on eBay for $30 and then bleed the system

How do you bleed the system for the sensor to the fan?

Just fix my 2003 Civic EX. Only one fan was coming on when the AC was on otherwise no fans would come on and it would overheat. I replaced the one fan that wasn't coming on when I turn the AC on and at that point I gained both fans coming on with AC. Still zero fans coming on without the AC switch on so I went and bought a fan switch which is located in the thermostat housing for like $28 so I replaced it, and everything works great. Happy camper all easy .

I have the same issue with the radiator coolant fan not working but I finally fixed it. Let me start from the beginning, I had an issue with a slow leak of engine coolant when I would drive to work, about a 70minute drive, the car would stay cool all the way to work most days, but I would start getting temperature spikes after two or three commutes to work. I wasn’t able to find the leak with my coolant test kit because the leak was so small so I decided to replace the radiator since there were no visible leaks from any of the hoses. I noticed when I pulled the radiator an area at the bottom where coolant had slowly been leaking and would evaporate thus no visible drips of coolant so I replaced the radiator and refilled the coolant by turning on the engine and running the heater full blast. After a while it appeared the system was filled so now I thought the issue was fixed but I noticed the same problem, temperature spikes after driving a couple days so I thought there might be another leak, I also noticed that the coolant fan would not turn on any more. I pulled the plug off the temperature fan switch and jumped the two terminals together with a paper clip and the fan came on so all the wiring, fan and fan relay were good. So I thought the fan temp. Switch was bad so I replaced it. Still the fan would no come on. So I bought a coolant fill kit for 20 something dollars and used it to fill the car. Same as before, turned on the engine and turned on the heater full blast and surprise the coolant fan started to work again. I also replaced the temperature sensor used by the temperature gauge. I think my issue was just still to much air and must have been a pocket of air where the fan temp. Switch was, so pressure wasn’t great enough to trigger the sensor and turn on the fan. The coolant loss after replacing the radiator was do to my radiator clamps not tight enough to restrain the coolant when it was at operating pressure, 1.1 atmosphere.

I need help with my 03 Civic I’ve changed the coolant switch and fan relays are but fans still don’t turn on and even while turning ima still no fans turn on ??