280z/280zx temp sensor position | The Z Club of Great Britain
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280z/280zx temp sensor position

Discussion in 'Exhaust & Cooling Systems' started by toopy, Jun 6, 2020.

  1. toopy

    toopy
    Z Club Member

    I currently have an electric fan temp sensor unit that sits in the radiator top hose, it works great, but i now want to go for a cleaner look.
    I have a later thermostat housing with several extra threaded holes, one of which I'm assuming is for the temp sensor shown in the pic.
    Is it a standard on/off sensor for fan control or am i barking up the wrong tree and it's a resistive type for connection to an ecu?
    And i will need a source for the wiring side plastic connector or a decent used example.
    Looking at the housing, i guess the small bolt in the top part could be for the sensor, or does it go next to the temp sender for the gauge on the bottom portion?
    temp sensorx.jpg
    housing.JPG
     
  2. Bazzateer

    Bazzateer
    Z Club Member

    Here's a pic of the fan sensor on my 260Z 2+2. Switches through the earth.

    20200606_163810.jpg
     
    AliK likes this.
  3. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

    Mine sends a signal to my ecu and then I set what temp the fan comes in and shuts down. I think one is classed as a sensor and the other a switch. Ideally you want one with the square type plug as they are universal so you can get a connector aswell.
     

    Attached Files:

    AliK likes this.
  4. toopy

    toopy
    Z Club Member

    I guess it does the job, but it definitely doesn’t look oem.
     
    AliK likes this.
  5. toopy

    toopy
    Z Club Member

    So the one in the pic I posted should do the job, if I can ascertain it’s just a switch?
     
  6. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

  7. Bazzateer

    Bazzateer
    Z Club Member

    Yeah, it's definitely been messed about with in the past, but it works perfectly.
     
    moggy240 likes this.
  8. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    I think thats a sensor, not a switch. a few years ago I looked long and hard and couldn't find a switch that fitted in the stock holes in the thermostat housing, but failed. they all seem a bit bigger.
    I think this one is representative - you'd need to tap the housing out to m14.
    https://www.ebay.co.uk/itm/183540536941
     
    toopy likes this.
  9. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

    I can't remember if I had to modify but luckily I will try and confirm what is what with these. IMG_20200607_094221.jpg IMG_20200607_094226.jpg
     
    toopy likes this.
  10. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

    I think your right Jon, I tried the ones I have and could not get them to switch. I know the blue one is a sensor as it is my spare for my car. Thinking about it I might have drilled mine out to fit the sensor aswell as the sensor part was slightly wider than the hole it was going in.
    Atleast with your one Jon you know what temp it is set to switch as they do them ones at different temperatures aswell
    The other thing is what type of thermostat housing you have as the later ones have more hole for sensors etc and if you are using a water heated inlet manifold for standard carb factory setup.
     
    jonbills and toopy like this.
  11. toopy

    toopy
    Z Club Member

    Thanks for looking into this and testing your sensors Mike, i had another look on rockauto at more vehicle years, but they all appear to be sensors not switches.

    The switch Jon listed seems like a good compromise, what temp would you guys recommend, rockauto list thermostats OEM temp as 180 Fahrenheit, so approx 82 Celsius, which would equate to a fan on temp of around 95 Celsius?
     
  12. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    I'd want the fan on by 85. I think stock thermostat opens at 82, so if it gets to 85 you know the thermostat is fully open and then temp is still going up.
     
  13. toopy

    toopy
    Z Club Member

    This from the ebay page for above switch,


    A good rule of thumb is that the on temperature of the switch should be around 12°C to 18°C higher than the vehicles rated thermostat opening temperature i.e. the temp the thermostat begins to open at.


    So for example if your thermostat starts opening at 74°C you want an "on" temp of 86°C to 92°C so you would use the 90°C on switch. If your thermostat opens at 82°C you want an "on" temp of 94°C to 100°C so you would use the 95°C on switch.

    Thermal switches available:

    • 80°C on / 72°C off (± 3°C)
    • 85°C on / 77°C off (± 3°C)
    • 90°C on / 80°C off (± 3°C)
    • 95°C on / 85°C off (± 3°C)
    • 100°C on / 90°C off (± 3°C)
    • 105°C on / 95°C off (± 3°C)
    • 110°C on / 100°C off (± 3°C)
     
    moggy240 likes this.
  14. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

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