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Water Temp Controller (Diy How To Instal)

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I've had this little gadget for a while now and have been wanting to try it out and get it tested.... and it works a treat! - so heres a little guide on how to install them and get them up and running.

These little units control the temp of your radiator for a fraction of the price of a proper thermo controller system.

The original design was to control the temp of fish tanks, therefore it has a heating and cooling function, more on this later.


******** Please note ----- I take no responsibility for mistakes you may make or things you may blow up during the process of this guide, all electrical work 'should' be carried out by an authorised auto elec. But if your feeling brave like me, and have a fair understanding of how electrical stuff works or are the type of person that has installed a few sound systems then you should be fine smile.png *********


They can be purchased on ebay, just search for "DC 12V Digital Thermostat Temperature Control" and you should find something like what i've shown in the picture.

Also heres a good link on how to use the controller - http://www.autospeed....html?&A=112617

Things you will need include -

- Temp controller

- Radiator fans (mine just cleared the power steering belt by 10mm)


- Relay that matches or exceeds the current draw of fans

- preferably an inline fuse (10a should be right)

- Basic set of tools

- Some electrical knowledge

- between 6 and 10 beers

All up it took me around 6 hours over 2 days, but I also installed a new sound system while I had everything apart.

So I decided to place it in the single din pocket below my radio, along with some other switches that operate my subwoofers and garage doors.

I measured out the size of the single din and went down to the local plastic store to have a piece of perspex cut, cost a few dollars, and then whipped out the dremel and drill and cut out holes for my garage door switches, sub controller and temp controller.




Pic of relay, inline fuse and temp controller unit.



Next I put the temp sensor probe next to my radiator temp sensor for my gauges. I drilled a hole (but didn't drill all the way through) and simply placed the probe in the hole with some special heat resistant glue stuff (hole was a tight fit).


note - the top and bottom radiator hoses will be at different temperatures, I've placed my probe in the top (hot side) as its near the same place the factory ECU gets its readings from. If you use the bottom radiator hose, you will be dealing with colder temps.

Its around this stage that you need to work out the wiring stuff, heres a handy diagram from that link I posted above that I followed, Its got all the pinouts on the relay so its real easy to follow.


You want to get your relay as close to your fans as possible (thats the point of them) I found an empty spot in my fuse/relay box and used that for my relay and inline fuse.


I had to run 2 wires through the fire wall one was the 12+ signal to activate relay, and other was for the temp probe, if you drill your own holes make sure you use a rubber grommet so the wires don't rub on bare metal, otherwise try to use an existing rubber grommet. (sorry no pics of this bit)

Once you've ran your wires through, I put everything back together and set up the controller, use that link I posted above to work out how to use it, ideally you'd like the fans to come on at 90 and turn off at 85, or if you'd like to run cooler then you can do so.



Its also a good idea to try to match the temps that you'd like to run with your thermostat, the OEM thermostat in the 34 gtt runs hotter than its 33 gtst predecessor. The 34 opens around 85 and is fully open at 90, whereas the 33 starts to open around 76?... I think and is fully open around 80?

The reason for the 34 being so hot is for omissions.

Side note - if you go and buy one of those cold thermostats (nismo/trident etc) that are fully open at 70 degrees, it will cause the car to "warm up slower". While your car is in this "warm up" mode the car's ECU will naturally add extra fuel to your map (in order to warm it up) and if your car is staying to cold ie. with a cold thermostat then your car will forever be adding extra fuel to the map (until it gets above a certain temp and ends 'warm up mode'), and this is why you see some cars driving around with black soot all over their rear bar.

So that ends my water temp controller install guide, hopefully this will help some people.

Just don't forget to read through that link about how to set it up and you'll be fine.

Cheers - Daniel

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