I have never heard my rad fan turn on, even on hot summer days. First thing i did was check the fan motor by running two wires directy to the battery, fan runs great. Next i know it gets switched on and off by the ECTS (engine coolant temp switch) on the thermostat housing. I unplugged the ects and bypassed it with a paper clip, fan turns on. So, i figured the ects was bad since the fan turned on when i bypassed it and i went on to get a new one.
The fan still wont kick on and my car is even overheating. Needle goes passed half all time and goes back down once the car gets moving again.
Not sure what else to look at, maybe the second ects i got is bad? (its not oem)
Good info there on the diagram. Check the the fan fuse inside the car first. If ok then check the fan relay circuit.As you can see the radiator fan switch ECT energizes the radiator fan relay. The relay should be on the right side of the radiator as you face the front of the car. There is a connector on the relay. I would suggest unplugging the relay and remove it and direct from the battery jump the relay coil contacts to see if it energizes. If it does while still energized use an ohmn meter and see if there is continuity across the two contacts. If the relay checks out do this. Find the two wires in the relay connector and connect the volt meter to the wires.Run the car until its hot leaving the meter on and see within 15 minutes or so if the meter ever registers 12 volts to it. If it does not then there is open circuit between the ECT and the relay connector. Check all connectors in the circuit. Also as a note there are connectors on the left of the radiator that are in the circuit. Check them , sometimes moving the wiring may sho up a loose connection. Good luck
Also when your engine is warmed up and running is your upper and lower radiator hoses feel about the same temperature. If the lower is much cooler or just warm the thermostat is not opening up to let the flow of hot water by that ECT switch to close to “bring on the fan”. Before you do the electrical test except for verifying the radiator fuse is good, bleed the air out of the water system. There is a bleeder nut next to the upper hose connection to the engine. Incase you dont know the thermostat is mounted low on the engine at the lower hose connection. If the thermostat does not open (besides being bad) it may be the air in the system is like air vapor is blocking the the water/temp down to the thermostat. Bleed the engine until no air and or water air mixture comes out of the bleeder. Hope this makes sense.
yes. I did not read your post throughly. Still make sure you bleed the system. Like I said before, if the lower radiator hose is a lot cooler than the upper the thermostat is not opening to allow the ECT to detect the water temperature so it can make contact.
thermostat must be the problem, lower rad hose was alot cooler than the top. I didnt suspect it because i swapped it out just a few months ago and the operating temp was fine. before i changed the thermostat the temp gauge was always cold, it fixed that problem so i figured it was functioning properly.
could be there is still air in the system OR the water pump is inop and not moving water. When you have the radiator cap off during warming up the engine do you see the water in the radiator flowing (bad pump?)
