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Thermo fan switch/Controller

Discussion in 'Electronics' started by dan1_721, Dec 22, 2007.

  1. dan1_721

    dan1_721 Guest

    I have a problem with both the radiator and AC fan coming on whenever the key is in the on position, regardless of engine temp.

    What controls/switches these on/off? What should I be looking for and where is it?
     
  2. 86GTMonkey

    86GTMonkey Well-Known Member

    I've got this same problem. Unfortunatly I don't know how to fix it either. lol
     
  3. zak062

    zak062 Well-Known Member

    its suppose to do that....
     
  4. JoeJack88

    JoeJack88 Well-Known Member Super Moderator Donated!

    no its not....my st had this problem and i fixed it
     
  5. zak062

    zak062 Well-Known Member

    then why does my track do it after i replaced all the relays and fuses?
     
  6. JoeJack88

    JoeJack88 Well-Known Member Super Moderator Donated!

    its a wiring problem or the fan switch is broken.
     
  7. MITT4G

    MITT4G Well-Known Member

    I have the that issue also- but since I dont have a working A/C I just wired Both fans together- And Ill tell you when we hit 100+ my temp never went passed 1/2 way on the gauge.

    I dont mind it being on- but I have changed my fans 3 times in in 2 years.
     
  8. dan1_721

    dan1_721 Guest

    The thing is, mine are stopping the engine from warming up apart from on very hot days (35 degrees celcius plus, tho down here it gets alot hotter at times). If i cant figure this out, il just wire it to a switch.

    Anybody have any idea? Il try cleaning the contacts, and il swap the relays. Past that, no idea, other than changing the coolant temp sensor, but apparently they arent related (altho wiring diagram shows that the fan runs straight off it!)

    Could this also be that the thermostat isnt working 100%?
     
  9. Mafix

    Mafix Owner Staff Member Administrator Donated!

    it's the fan switch not working. it's in the bottom of the rad near the lower hose. start there.
     
  10. dan1_721

    dan1_721 Guest

    Thanks alot MAFIX, exactly what I was hoping for :D
     
  11. ST165-2765

    ST165-2765 Well-Known Member Donated!


    I would guess that your thermostat is NOT 100%.

    Your thermostat should stay closed until the engine warms up so you should not have coolant flowing from the radiator into the block so having the fan on cooling the liquid in the radiator should not make a difference.
     
  12. ST165-2765

    ST165-2765 Well-Known Member Donated!

  13. dan1_721

    dan1_721 Guest

    Il check to see if the switch is plugged in 2moro morning, its 1230AM now here. If its plugged in, i guess il snag one from the wreckers.


    Also il grab a thermostat, but how hard to change is it?
     
  14. ST165-2765

    ST165-2765 Well-Known Member Donated!

    See page CO-16 3rd picture down where it says "Water Inlet" your thermostat is inside that part. So to change your thermostat

    -drain the radiator
    -follow the bottom radiator hose to where it attaches on the block (under the altenator 3sge) this is the "Water Inlet"
    -disconnect radiator hose from "Water Inlet"
    -unplug the temperature sensor
    -undo the 2 nuts/bolts that attach the "Water Inlet" to the block
    -remove the "Water Inlet" & thermostat
    -clean the surface of the block & "Water Inlet" of the old gasket
    -install new thermostat
    -install new gasket
    -install "Water Inlet"
    -attach temperature sensor
    -attach radiator hose to "Water Inlet"
    -refill radiator
     
  15. dan1_721

    dan1_721 Guest

    Will have a look, and maybe grab one today. At least its overcooling rather than undercooling. Maybe i should just leave the fan switch, as surely it wont do any harm having them run all the time?
     
  16. ST165-2765

    ST165-2765 Well-Known Member Donated!

    Just more wear & tear on the fan motors so pick up some extra motors at the wreckers.
     
  17. dan1_721

    dan1_721 Guest

    I think i swapped the switch today. LOL. Cant tell if it made a difference yet, has been 40C today! IS the switch the one that screws into the coolant neck, on the left side of the front of the motor, next to the lower rad hose, with a circular plug with a single blue wire I think?
     
  18. dan1_721

    dan1_721 Guest

    I know this switch is meant to be in the bottom of the radiator, but i cannot find it there. I think its the one in the thermostat housing. But I have tried 4 of those with no luck, the fans still just come on. I think its this one becuase it has a blue and black wire, one of the wires to the rad fan is blu and black. WTF?
     
  19. ST165-2765

    ST165-2765 Well-Known Member Donated!

    You have the right one on the thermostat housing. All Tracs have them in the radiator.

    So either a previous owner has wired the fan to stay on constantly or you have a broken wire to the temperature switch.
     
  20. dan1_721

    dan1_721 Guest

    I dont remember them staying on all the time before though. Il 100% make sure in the morning when the car is cold. I had 3 new thermostat housings from the wrecker, tried all the sensors and they all made no diff. ARGH! but now the car should warm up. It had no thermostat at all! does now :D My housing was all brown and yucky though, as was rad cap, although cooolant was green. When I do the oil and filter, il flush the coolant and refill it.

    Can i test somehow to see if the wire is broken?
     

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