Azlan

I have 92 Honda Civic 4drs EG9 with D16A9 engine(auto trans).The problem is the radiator fan is not working after 20 mile driving but the funny things is the car not overheat(the temperature gauge still nearly half).The warning light comes on while driving,exam it after that and the problem is the ECT problem(6 blinks)(don't know the problem either the ECT switch or ECT sensor).First i wired the fans direct to battery,it's working.Secondly,i jumper the ECT switch connector,it's works(the fans relay makes a click sound).I've change the ECT switch a few days ago but still no luck.Please help me,really confuse right now...

Duane_in_Japan

The ECT 2 wire sensor is monitored by the ECM and does not care if you are overheating, the single wire fan switch is not monitored. Do not trust your gauge to show that the engine is getting too hot or is near overheating. These gauges are not calibrated that well, it may not show overheating until after steam is coming out from under your hood.

I think that the thermostat is stuck closed and not allowing hot water to get to the fan switch to turn the fan on. Also 20 minutes driving is not enough to overheat the engine severely. Start the car and monitor the temp of the radiator hoses by hand, I think you are not getting any water circulation and the lower hose is not warming up at all, you can go for quick drives around the block and check hose temps every couple of minutes.

The warning light is a different switch that may be mounted directly in the head so it knows that you are getting too hot before the fan switch and temp sending unit for the gauge, also probably a single wire sensor, sees a problem.

If you have AC, both fans should come on but I think that the overheat warning light may still come on after 20 minutes since I think no water is circulating. But try this after you test the hose temps.

Azlan

thanks for the quick reply.i didn't put any thermostat for 2 year since i bought this car.Switch on th a/c but still the radiator fan not working,just the condanser fan works.Just runs the car for 15 km and stop,checking the upper and below hoses are hot and the fans still not working.The warning lights don't come on as before.

virgineg6

try bleeding the system make sure it has no bubbles and is full all the way up to the filler neck this would cause the switch not to work

Duane_in_Japan

The fan should work with the AC on. Now you have to hotwire the fan motor. If it works then see how many pins on the fan relay have power. If two pins have power then bypass the fan relay, if the fan works then diagnose why the relay coil is not being energized, or a bad relay. We will go from here.