radiator fans turn on with ignition
 

hi, i have a toyota camry 1998 4cyl. (5s-fe engine).

when i turn the key to the "on position" the both radiator fans turn on while the a/c is off. i have checked fan relays 1,2,3 and they are all good. voltage tested the ect sensor connector (reads 5v).

could it be a faulty fan switch in the radiator? i checked the voltage and it reads 12v from the connector. what should i do from here to solve this issue?

The fan switch is CLOSED when the coolant temp is below the set point needed to turn on the fans.

If the switch fails in the OPEN position or the harness plug to the switch is disconnected or there is an open wiring fault to the switch. The fans will turn on.

Check for an open switch or wiring issues.

thanks i will do that.

how much voltage should be flowing to the cooling fan switch connector when car is on? should it read 12v?

Use an ohm meter on the switch. The switch should be closed.

The switch will always have 12V if the ign switch is on.

OK i replaced the cooling fan switch, i just plugged it in while leaving the old one in the radiator, a/c was turned off and both cooling fans connected and they both still turn active when the key is in the "on" position, car was dead cold.

Did i do something wrong or could the problem lay else where?

i tested the new switch and it has like only 0.03-4 ohm of resistance so its good.

The temp switch plugged in or not makes no difference in the fans being on or off?

Is there any change in fan speed (faster/slower) when plugged into the switch or not?

You checked the relays to make sure the relay power switch turned off when the solenoid is not powered?