Outer Limits 4x4 Board

Just wondering what people use to turn on theyre thermo fans when coolant gets to a certain temp, and off when it falls below.
All i can find are the basic 'mechanical' jiggers for like over $50 each, which is a little pricey i think for a basic device.

I too am interested in this, I have seen a few with temp switches soldered into the radiator, but where do you get the switches that are the right temp?

I use the Davies Craig 0401 switch (1 thermo fan, no air-con) from Supercheap, about $50 from memory.

http://www.daviescraig.com.au/documents ... ctions.pdf

The DC ones are adjustable, you set them to switch on when the needle of the guage reach's the needle thickness over normal operating temp if that makes sense ?

Im using a thermostat switch from JayCar. i use it to switch on/off the solonoid-relay. Only worth about $3-4

I have it clamped onto the top header tank of the radiator. it switches on at 70deg and will reset when temp drops below 70

keeps engine at about 85 when sitting at idleand will last for 50,000 cycles.

Cat no- ST-3833 70 deg
Cat No- ST-3836 100 deg

You can buy aftermarket thermo fan switches for just about anything.
If you go to a decent auto shop you'll be able to flick through the catalogue and find something with a suitable thread and on/off temps you desire.
I just fitted EF thermos to my GQ. I used the original O/D temp switch fitting in the lower hose outlet of the Radiator and an 85 on, 80 off switch.
You'll find the radiator will pull 10-15 degress out of the coolant so my engine temp is cycles around 95 degress which is perfect.
I don't like the capillary fittings that you stuff under the hose. They leak. The switches fail and if you get low on coolant they're erratic. If you fit the switch in the bottom hose it'll work if the coolant level gets down.

It's also a good idea to use a change over relay to operate the fans and wire them into the N/C circut. That way if the swtich or relay fail the fans go on..

Cheers Dan

Thanks for responses guys. Im going to drill and tap next to the original temp gauge sensor and use a Tridon temp sensor. I got a 95on-90off sensor, im hoping thats not too high a setting.

PJ.zook wrote:Thanks for responses guys. Im going to drill and tap next to the original temp gauge sensor and use a Tridon temp sensor. I got a 95on-90off sensor, im hoping thats not too high a setting.

That will be fine in the top.
That's often the first mistake people make is going too cold. Remember engines are designed to work around that temp. Colder is not better. Those people than run around with there temp gauges down at a quarter or less aren't doing themselves any favours.

I got one from the wreckers. Not sure what japanese car it's out of, but it screwed straight into the thermostat housing on my Isuzu diesel.

The thermostat housing isn't the best place for it. But I haven't got around moving it yet, I just put up with the fans switching on early and pretty much staying on.

My fans run full time and I leave it upto the original thermostate to open and close the water flow.

LudaCris

thats a waste of power from the alt especially if running lights and winch.

Yeah I have got twin alt's and run the winch separate to everything else. Also car is only run on the race track so no highway runs where fans are not needed.

LudaCris

Ruffy wrote:That will be fine in the top.
That's often the first mistake people make is going too cold. Remember engines are designed to work around that temp. Colder is not better. Those people than run around with there temp gauges down at a quarter or less aren't doing themselves any favours.

Sweet, good to hear, was worried that it was a bit high. Pity the switches had a wider temp range, ie on at 95, off at 85.

built4thrashing wrote:thats a waste of power from the alt especially if running lights and winch.

Mine pull 15 amps (under 200w). Not a problem for me, but others may not have the same to spare.