My radiator fan will not come on when engine gets hot. The fan comes on with the a/c. I have changed the relay and the cooling temp sensor. I think the only other thing is to change is the radiator fan switch. My question is how do I change this. What do I have to take off to get to it. My car is a 92 firebird 305 tbi. Please help and if there is any other thing to check please let me know.Radiator fan not working?If yourun direct voltage via a jumper wire from thebattery to the fan motor, the fan should come on. Are you sure you got a good relay? Have you checked the entire cooling system, to see if there were any other problems, as you swapped out the coolant sensor which will tell the fans when to kick on and off. Is your thermostat ok, water pump weeping any coolant out of the weep hole, flushed your coolant system at all, emissions systems ok,ie: catalytic converter not partially plugged. The switch for the coolant is essentially the fan relay that you already replaced Check all of your grounds in that circuit,make sure they are clean and tight,because if you areputting battery voltage right to the fan motor and the fan is kicking on,then look at the aforementioned suggestions and eventually you will get to the source of your problem. That relay sounds like it's only doing half of it's job. Good Luck.Radiator fan not working?you best bet is to go to the parts store and buy the manual for your car. Haynes manual has some really good pics and instructions on how to tear your car apart down to the frame. I have a chiltons but I use the haynes manual more.
Go and get one for your car. they are handy to have and a very good read if you like that stuff.Radiator fan not working?That car has two temp sensors, one on the top front of the intake manifold near the upper rad hose with 2 wires, a yellow and a black. It also has a sensor on one of the heads, between two of the spark plugs, with a single green wire. The one with the single green wire is for the gauge ONLY. The one with the yellow/black wires is for the ECM and this is the one that controls the fan (indirectly).
The computer (ECM) itself sends out the ground signal to energize the fan relay. This signal is sent out at approximately 220*, based on the reading from the main temp sensor (yellow/black wires). If the sensor is new, and the ecm is ok, then there could be a wiring problem, or coolant circulation problem.
Also make sure the cooling system is full. The main sensor is in the top of the engine, and if the coolant is low, no coolant will flow past the sensor, and it will always register cooler than it should.Radiator fan not working?you can toggle switch it or wire it directly to the battery. maybe even wire it to your ignition so when the key turns on so the fan.
