Guide - How to wire up thermofans

[chaserbuddy]

hey, i was just wondering if there's anyplace for a thermo switch on 1jz? and im a bit of a noob at this whole electrical wiring stuff what are those black box thingy's and where can i get them?

thanks David

[LeeRoy]

hey, i was just wondering if there's anyplace for a thermo switch on 1jz? and im a bit of a noob at this whole electrical wiring stuff what are those black box thingy's and where can i get them?

thanks David

You could get a thermoswitch from toyota but it would cost you your firstborn most likely.

The black boxes are relays and are mounted in relay holders, both of which are available from repco, supercheap, etc.

[chaserbuddy]

i think ill just go with a switch inside the car somewhere, just switch it on when the car is warm/hot, until i figure something out. 1st post states that they are abundant in wreckers should be able to fit it somewhere in a hose and earth the connector. It was wired up before hand with some type of oven switch haha.

[VA61DETT]

Hi

chaserbuddy.

You can always do what I used to do and use one of these to drive you thermo fan relay:
http://www.altronics.com.au/index.as...=item&id=S5595

I used to just bolt em on to the thermostat housing with an ally tab.
Good for a quick & cheep solution
Just make sure to get the 'Normally Open' type.

-A

[chaserbuddy]

Hi

chaserbuddy.

You can always do what I used to do and use one of these to drive you thermo fan relay:
http://www.altronics.com.au/index.as...=item&id=S5595

I used to just bolt em on to the thermostat housing with an ally tab.
Good for a quick & cheep solution
Just make sure to get the 'Normally Open' type.

-A

would i be able to get one of these at a local shop, like jaycar or repco/ sprint etc? or will i have to buy from altronics?

cheers

[VA61DETT]

Yer Jaycar have em,

well on the website anyway:
http://www.jaycar.com.au/productView...Max=&SUBCATID=

However they are only 70 degree ones, or 100 degree.
70 is a little cold, 100 is kinda too hot.
you really want 80 - 90 degree ones.
70 would prolly do ok, will at least allow the engine to heat up faster.

The problem with these switches are the hysteresis is way huge, so once they trip the fans
will never turn off under normal driving conditions.

-A

[chaserbuddy]

Hi

Just make sure to get the 'Normally Open' type.

-A

is this a typo or something cos the 1st post says get a normally closed type? ill see if i can get both because there cheap and if ones wrong ill use the other

[LeeRoy]

A normally closed switch will require two relays. The plus side however is that if the switch fails then the fans will automatically kick in, effectively acting as a failsafe. The majority of standard thermoswitches are normally closed.

A normally open switch will only require one relay but if the switch fails then the thermos won't kick in.

[VA61DETT]

Aah Yer I may have stuffed up some where,

You can use either, just means you will need an extra relay
(^ what LeeRoy said)

I have used a NO type setup for about 2 years on my car, till just recently
Now I built one of the jaycar voltage switch kits to get more accurate control over cooling.
(decided to put more effort in since I just rebuilt the motor)

-A

[chaserbuddy]

the thermos wont kick in for some reason, i think its to do with the thermo switch not getting hot enough. i have mounted it onto a small bit of aluminum which is connected to the front/side of the waterpump, just below the two standard water thermostats? this should get easily enough heat...? 70 degrees isn't that much so there's no reason why is shouldn't kick in.

[VA61DETT]

What kind of setup did you end up going with?
Have you tried opening / shorting the thermo switch to test the relays?

I usually mount the sensor close as possible to the thermostat housing on the head.
Though the water pump housing should get hot enough.
The sensor base needs to be secured on a flat surface, if there is an air gap it may not switch.

-A

[chaserbuddy]

same setup as shown on the digram altough the 1st relay is pointless LOL! could just run a wire straight from ignition, also the pin that goes to the thermo switch is in the bottom vertical pin instead of the middle pin i assume witzl fucked that up on the diagram...shorting the thermos switch to earth makes the fans work so its def the thermostat switch, on a flat surface and earthed NC thermo switch also...maybe it doesn't get hot enough also is it supposed to be earthed from the base or is it earthed from one of the two pins at the top, cos i have tried earthing it from a top pin also...but still wont work! god damn cheap switches...

[LeeRoy]

Is the place it is mounted actually grounded? Cause if youve installed it between 2 hoses then it wont ground.

If youve got a normally closed switch and shorting the wire to ground turns the fans on then youve not only wired it up wrong but the fans will be on permanently.

Sure Witzls paint skillz arent fantastic but the diagram is perfect and works equally as well. If you followed it then you wouldnt be here posting about why your fans don't work. The 2 relays are needed because you need to throw the 85a pin to 85 so it doesnt run the fans all the time.

If your using a normally closed switch then this is the only way to do it. A normally open switch can be wired using a single 4 pin relay but lacks the failsafe of turning the fans on if the switch dies.

[Mos]

same setup as shown on the digram altough the 1st relay is pointless LOL! could just run a wire straight from ignition,

Why don't you ask the question rather than making an inaccurate statement?
The first relay is needed because it switches the high current required to run the thermo fan. Sure you can hook it up straight from your ignition switch, but you would need reasonably thick cables from the ignition switch to the second relay (thin cables will also work (for now) - doesn't mean it's right) and you reduce the lifespan of your ignition switch.

If you're going on the dodgy you might as well use the thermostat itself to switch the fan current. The altronics one is rated at 10A, enough for one fan - that way you don't need any relays and saves complications (for now).

also the pin that goes to the thermo switch is in the bottom vertical pin instead of the middle pin i assume witzl fucked that up on the diagram...

I'm sure 4 pages-worth of people didn't pick up the error - thanks for your expertise...

but still wont work! god damn cheap switches...

Yes, blame the switch. Your understanding of how it works is beyond question... *sigh*...

shorting the thermos switch to earth makes the fans work so its def the thermostat switch,

Shorting the thermostat makes the fans turn on? In that case you have wired it up for a NO thermostat...

on a flat surface and earthed NC thermo switch also...

...but yet you say you bought a NC switch?

maybe it doesn't get hot enough also is it supposed to be earthed from the base or is it earthed from one of the two pins at the top, cos i have tried earthing it from a top pin also...

The housing of the thermostat performs only a mechanical and thermal function - the electrical function is performed by the two terminals - so one terminal would go to the relay, the other terminal would go to ground.
Why don't you post photos of what you've done? It will be too hard for us to talk you through it because you're rejecting a correct diagram/solution. You either know, or not, you can't have it both ways.

Mos.

[chaserbuddy]

well it turns out that i got two normally open switches instead of one no and one nc...
this is what i had done...



wrong switch and relays are not much help, bad luck and knowledge doesn't do anyone any good. sorry for being an annoyance aswell just frustrated because i couldn't figure it out.

also my two original relays show that pins 87 and 87a are not connected which is why they power wasn't going to the fans...these are the three relays, i have 2 of the 1st and one of the second,


I don't think either will work with the method shown by witzl. so i am going to just wire a simple NO setup now instead...

cheers