Electric cooling fan question, which thermo switch to use


  • Electric cooling fan question, which thermo switch to use

    I was at the junkyard yesterday, snagged an early maxima (91-94) dual cooling fan assembly. I was looking at xenonz31's info and searching on the forum but can't seem to find the information i found before. I seem to recall someone using a painless kit, but can't find the info on it. I found a painless kit on summit, but i don't know if there is a specific one to get or if they're all the same. Still need to buy a maxima alternator, but wanted to start getting the pieces together, sound of the mechanical fan is driving me crazy. On the Z31, does the temp probe from those kits go into the radiator, or block?

  • #2
    Some of us use the 1991-1994 Nissan Sentra 1.6L thermo switch. Switches on at 190*F, turns off at 180*F. It is more durable than aftermarket thermo sensors.

    This thermo switch is located on the thermostat housing next to the water pump. So that means belt end of the engine towards the firewall.

    Do not put any thermo switch for electic fans in the lower port of the Z31 radiator. The car will be overheating before the sensor gets hot enough in that spot to turn the fans on. It is best to put the sensor in the upper radiator hose.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily

  • #3
    I was thinking about doing e fan in my z too…
    I did some research on the ac condendser fan circuit.
    I'll probably attempt to utilise the oem wiring harness to use the stronger fan from the ford Taurus in place of the oem condenser fan.
    Just my idea.
    http://z31performance.com/showthread…2-2-(-now-NA2T
    My build thread (:

  • #4
    NissanEgg;346543 wrote: Some of us use the 1991-1994 Nissan Sentra 1.6L thermo switch. Switches on at 190*F, turns off at 180*F. It is more durable than aftermarket thermo sensors.

    This thermo switch is located on the thermostat housing next to the water pump. So that means belt end of the engine towards the firewall.

    Do not put any thermo switch for electic fans in the lower port of the Z31 radiator. The car will be overheating before the sensor gets hot enough in that spot to turn the fans on. It is best to put the sensor in the upper radiator hose.
    Do you know of an aftermarket or OEM section of metal pipe with a bung in it that you can splice into the upper hose and will work with that sensor?

    edit…google is my friend…derp.


    84 AE/Shiro #683/Shiro #820/84 Turbo

  • #5
    Can see my build thread to see what I did.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily

  • #6
    Kind of a nub question, but for those that have wired toggle switches into the cabin, where is a good place to feed the wires from the engine bay? I am thinking of putting them over in the center console near where the adjustable shock switch would be.
    Justin
    1986 NA 2-seater
    SCCA Solo E-Street Prepared #31
    Race Videos
    Build Thread

  • #7
    That temp switch can be installed on the drivers side of the LIM as well.
    - VG30DET (HE341) 86 300ZX - 1982 280ZX Turbo - Headered NA 1986 300ZX 2+2 - 2000 Xterra -

  • #8
    There is 2 ways you can do this. You can buy a premade relay setup that uses a probe that either goes through the radiator fins or goes into the coolant hose. Flexalite makes one http://www.amazon.com/gp/product/B00…VYDTW2VS404FNB

    http://www.amazon.com/Flex-lite-3116…sim_sbs_auto_1

    And flexalite makes this one http://www.amazon.com/Flex-lite-3114…sim_sbs_auto_2

    The difference is that the first 2 is nicer, and one of them is variable where it will run the fan first at 50% power, then if it gets hotter it will go to 100%. The last one is basic, on and off and each one can be wired into the AC system to work. I personally have the VSC one (second link) and wire the bung off of the lower radiator to it as a backup. If for some reason the fans don't turn on with the probe in my fins, the bottom one will automatically switch it on if need be.

    You can also just do the temp bung like everyone else says and make your own wiring with a relay.

    Either is up to you.
    My Build Thread

  • #9
    Nissanegg, in your build it looks like you put the temp probe at the radiator unless you were referencing a diff picture. If anyone has pics of where/how you installed your probe that would be awesome. Wiring I can handle just want a good accurate place for the probe. I guess keeping the probe as close to where the upper hose comes into the radiator would be best?

  • #10
    michaelp;346589 wrote: That temp switch can be installed on the drivers side of the LIM as well.
    ahh, that's the ticket. I remember something about a temp switch being installed in the injector fan switch location
    but i was thinking it was the pathfinder CHTS. Do you know if it needs to be re-threaded for the sentra thermo switch?


    84 AE/Shiro #683/Shiro #820/84 Turbo

  • #11
    http://z31performance.com/showthread…2-2-(-now-NA2T
    My build thread (:

  • #12
    Modelli;346608 wrote: Nissanegg, in your build it looks like you put the temp probe at the radiator unless you were referencing a diff picture. If anyone has pics of where/how you installed your probe that would be awesome. Wiring I can handle just want a good accurate place for the probe. I guess keeping the probe as close to where the upper hose comes into the radiator would be best?
    I initially put the sensor in the bottom of the radiator. Car overheated before fans turned on. Put the sensor in a hose adaptor after drilling out the hole and threading it for the sensor. That blue thing in the later pics is the hose adaptor thing.

    Can also putin LIM as MikeP stated.

    I ran my toggle switches for manual override in the center console. Ran the wires under the center console and then snaked them out thru the hole in the firewall for the vacuum hose for AC controls so they come out near the battery.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily

  • #13
    Z_Karma;346611 wrote: ahh, that's the ticket. I remember something about a temp switch being installed in the injector fan switch location
    but i was thinking it was the pathfinder CHTS. Do you know if it needs to be re-threaded for the sentra thermo switch?
    I've put the pathfinder CTS in the LIM as well, on VG33 builds, for the EFI control. It creates a bit of a conflict if you want to run that, the temp switch and the gauge....You could probably drill and tap another hole for one if you wanted, though.
    - VG30DET (HE341) 86 300ZX - 1982 280ZX Turbo - Headered NA 1986 300ZX 2+2 - 2000 Xterra -

  • #14
    862sik;346600 wrote: There is 2 ways you can do this. You can buy a premade relay setup that uses a probe that either goes through the radiator fins or goes into the coolant hose. Flexalite makes one http://www.amazon.com/gp/product/B00…VYDTW2VS404FNB

    http://www.amazon.com/Flex-lite-3116…sim_sbs_auto_1

    And flexalite makes this one http://www.amazon.com/Flex-lite-3114…sim_sbs_auto_2

    The difference is that the first 2 is nicer, and one of them is variable where it will run the fan first at 50% power, then if it gets hotter it will go to 100%. The last one is basic, on and off and each one can be wired into the AC system to work. I personally have the VSC one (second link) and wire the bung off of the lower radiator to it as a backup. If for some reason the fans don't turn on with the probe in my fins, the bottom one will automatically switch it on if need be.

    You can also just do the temp bung like everyone else says and make your own wiring with a relay.

    Either is up to you.
    I'm running a Derale unit similar to the 3rd one with my dual fan setup from a Chrysler 300M. Works well. Have the probe in the radiator near where the upper hose connects. According to Nistune, with it idling and the fans cycling on and off, it sits around 190 or so.
    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build

  • #15
    I run my probe under the top of the radiator hose about 5 lines down, I get very good and accurate results.
    My Build Thread