Question about 1990 Toyota Corolla

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Sensor Wire/Fan 1990 Toyota Corolla

For what sensor does that wire on the bottom of the radiator go to? 
And also, my fan doesnt work at all, I tried replacing the relays, and

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  • Adrian Walker Dec 11, 2008

    -continued-- it still doesnt work. Oh yeah its a sedan with a 4A-GE swap

  • Adrian Walker Dec 11, 2008

    I know there is a sensor, but WHAT is the sensor FOR? There are two wires, white and a black and they lead to the upper left of the rad support.

  • Adrian Walker Dec 11, 2008

    nope, nothing

  • yadayada
    yadayada May 11, 2010

    if it where the fan switch when u touched the wires togeather the fan would have run, nope wrong answer from


  • yadayada
    yadayada May 11, 2010

    if u touch the wires together with the engine running does the radiator fan run? if no check if any indcators come on in the dash display.

  • yadayada
    yadayada May 11, 2010

    Only one wire?



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These wires could go to a temperature sensor for the radiator fan. The best thing to do is to bypass the sensor and straight wire the fan to come on when the engine is running. I had one to over heat because the sensor went bad and wouldn't let the fan come on.

Posted on Feb 07, 2009

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There is a sensor screwed into the bottom of the radiator

Posted on Dec 11, 2008

  • O Mclean Dec 11, 2008

    That's the radiator fan switch, its turns the fan on. when the water in the radiator get hot enough to be cooled



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Look for:
a bad relay
" " fan
" " " switch
" " temp sensor
a loose, corroded or broken wire at the temp sensor at the bottom of the radiator.
Start with the relay. Buy or borrow a Haynes manual for this car, lotsa pics.
You will need a continuity checker (cheap)

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