Installing Thermos

So after removing the aircon i had everything apart so i ordered a larger aftermarket alloy radiator and some silicone  hoses, then i thought to myself i might as well put thermo fans on the new radiator and remove the mechanical one on the engine.

The radiator is made to be bolted straight in with no mods. The thermos on the other hand are from an EF Ford Falcon which are pretty much the same as the BA, AU, and EL they required modifications.

The Parts

Radiator from FLYN.COM.AU
Thermos from wreckers
Tridon TFS139 Thermo Switch Rated to kick in at 85c and turn off at 80
Pipe Frabricated to hold the thermo switch on upper radiator hose
(The Thermo switch above uses a thread which can be found in magna radiators.)
Cable 6mm 25amp
Cable 5mm 15amp
Male & Female Electrical Connectors
Solder Iron
Trusty Cable Ties

1. Fit Thermos to the Radiator

See the below picture, this shows where you must trim / modify to make it fit the Flynn Radiator.

a) On the left and right edges there are 4 protruding mounting points, cut those off with a hack saw or a hot solder iron.

b) Cut a hole in the top of the thermo where the top pipe goes.

c) Cut a hole in the bottom for the bottom pipe

d) On the flynn radiator there are two tabs with holes that come out, this made mounting easy all i did was solder iron out some slits for the tabs to go through, which once fitted allowed me to just put some peices of rubber through the tab holes to hold it in place

Note be careful to measure and test fit as you go, and make sure you dont cut the wrong side like i did for the bottom pipe, doh.




2. Mounting

With the flynn radiator you can use your stock mounting points, noticed that mine sat alot higher than it should, i fixed this by taking the rubber grommit things from the bottom of the radiator and cutting one ring off them then i drilled out the grommits to make them fit over the thicker part of the spike they go onto this lowered it enough, other than that make sure you just put the stock brackets back on the top of the radiator to secure it.

3. Wiring

The most fun part, NOT…

Don’t be dodgey use a solder iron, last thing you want is a wire coming loose and shorting somthing out or worse causing a fire. I also used some heat shrink sheathing.

There are many different ways you can wire these up, this is how i did it.



Please also see this diagram which shows another way to wire it up with Aircon

Click to Enlarge

Above diagram provided by FYJOSH from

4. Thermo Switch

thermoswitchI spent alot of time on how and where i was going to put this, eventually it was decided i would cut up my new silicone top hose and get a pipe made up to put in it with the switch in it. I got this done by a radiator shop in Airport West he used a magna thermo switch radiator thread and copper welded it onto a peice of pipe.

The problem with this is that the switch needs to be grounded to complete the circut when it reaches temperature and with two peices of silicone on each end its not going to work to well, i stripped the ends off a peice of wire and ran it through the pipe on the engine side.

This caused another problem, it was leaking due to the wire in the pipe just drips though, i tried using T bolt clamps on it instead this helped but when it heated up it still started to drip a little so i am going to have to reassess that part of it, other than that it was a great success!


5. Finished

I am not very technical when it comes to cars so this took me all weekend to get right, and i still need to fix the leak on the thermo switch join.

I took this opportunity to also clean up my vacum lines going everywhere, thanks go to Dazza for showing a noob what i need to do hah

All in all there is a crap load more room in the engine bay and im pretty happy with it apart from the leak which i need to fix.

Click to enlarge

Click to enlarge

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