The Themofan Switch Adaptor Thread - With superawesomeness Speco Adaptor Stuff.

[AndyTTR]

Had the same problem when putting the Gen 3 in the Celica - I got the thermofan switch cut out of my old thermostat housing and welded onto the new one - only cost $10 at a local mechanic.

[omp]

^^^Yes very similar to what I had done! It does look very neat!

[richzx]

So can we confirm that the Speco part fits the hydro fan sensor for the bottom radiator hose? I have to order this and want to be 100% sure that the sensor fits into this adaptor. It's a pretty chunky sender unit and is the thread compatible with the Speco part.
Any help appreciated.

[MRMOPARMAN]

I use the 'voltage switch' Jaycar kit. This taps into/shares the temp sensor that my aftermarket water temp gauge on my dash uses.
If you do find a neat way to control thermo fans (perhaps with a tridon screw-in 100-95 switch) please let me know, as I reckon cutting into radiator hoses is a messy way to do it.

woudnt it be possible to use that jaycar kit but tap into the ecu temp wire?

[richzx]

No he has aftermarket thermos whereas I am using the factory 1J hydro fan which has a very large sender unit. It's been unplugged so far but as it's warming up I had better get it working.

[thechuckster]

or we could get the ECU (assuming we're using aftermarket here) to drive the thermo fan without needing another engine temp sensor? Even Simon's old Haltech (which needs a laptop running win3.1 or win95 to tune it) can drive a thermofan relay.

[Ribfeast]

Clever idea feeding off the factory temp sender, I should have thought of that I find the Jaycar one varies a bit depending on the voltage of the power supply. It's quite common for it to come on, and not turn back off, which drains the battery faster than the alternator can keep up, or at least puts excess load on the alternator.

I recently just ordered a Tridon TFS113 temp switch, will see how well that controls things. 97C on, 92 or 93 off (I forget). $46 or something from supersteep. Repco wanted $130 or something!

[Jabtronic]

Just a quick question, I just purchased a JAR alloy radiator, would it be relatively easier to get a 'boss' (or an M16x1.5 threaded nut.. basically?) welded into the bottom tank? Instead of stuffing around with the speco adaptor.. Any problems with doing it this way?
Cheers

[Ribfeast]

Isn't the bottom tank the cooler one? Better off putting it into the top tank?

[Mos]

Isn't the bottom tank the cooler one? Better off putting it into the top tank?

Factory generally places it in the bottom tank.
Mos.

[takai]

FWIW, i was searching around for other stuff and realised i had never updated this thread.
The Speco 5/8" adaptor works a treat and all bolted up fine.