I just want to know. Why did my radiator fan motor didnt operates when the thermostat open up? Mine use the electric fan instead of fan clutch. I’ve clean, changed the waterpump, relays, new wiring and sensor, fan switch but the fan still did not operates, unless I by pass the signal to direct than the engine temprerure cool doen, otherwise it will overflow on the expansion tank. I’ve just major overhaul the whole engine and have water jacket tested on lately. Its the 3K toyota engine year 1982 .
The 1 wire temp sending unit for the gauge/light
The 2 wire temp sensor for ECM and fan
Your car has both, and they are different.