Guide - How to wire up thermofans

[The Witzl]

i'm going to be installing a temporary digital display of the coolant temperature in the crown... because im really interested to see just how stable it keeps the temps with all the acilliaries on that car.

[bbaacchhyy]

A lot of the above has seemed to gone over the top (as most tend to do on Toymods).

.

I'm not sure what you menat by that ?

The info above was just some data of what they do for production cars, and whilst it is more complex, car companies don't spend money for things they don't have to.

Personally, I'll 99% stick with my setup (both fans come on at once), but I'll look into the data once I get it.

If it is not too hard to rewire, i may do it, but letting the temp get to 110 degrees is a bit scary for me.

Anyways, food for thought

Cheers

Michael B

[wagonist]

Yes, I do, but not online unfortunately. I'll try to get something scanned but it won't be a priority I'm sorry.

You can use it on aftermarket fans also, although if they're heavily mismatched you can get unpredictable effects. The two aftermarket fans on the sprinter were wired in such a fashion.

Mos.

I'll try to organise a time to come over & get a copy then.
I'll be running 2 identical aftermarket fans, but I like the idea of running them slower when its not necessary.
The Subaru factory fans for the ECU I'm running have 3 wires on them for half speed running (but these fans won't fit in my installation) & the ECU controls the fans anyway from a temp sensor which is in the feed pipe to the block.

[TurboRA28]

Cruzida, you wouldn't happen to have part number of that tridon switch would you? I've been hunting around for ages and all I've come up with is a 85on, 80off switch. This is too low. 95/90 sounds perfect.

Cheers
Joel

[CrUZida]

Ummm, sorry. I don't have it on me, but I may have it at home.

Go to somewhere that has the catalogue, there is about 50 to choose from.
All different temps, different threads, different pins (some 1, some 2, some 3)

Mine was a 14x1.5 from memory, I'll try and dig it up at home.

[bbaacchhyy]

Do as CrUZsida suggests, but also check the prices. They can vary from $40 to $150 for something that does the same job.

I ended up using one from a Nissan Prairie !!!

[CrUZida]

Mines from a BMW of sorts.
But yes, Bbaacchhyy is right, they do vary in price.
I'm not sure if its quite the range he said, but the one I got was about $70 retail, $50 trade.

[bbaacchhyy]

The Tridon one I got for the Priarie was $56, the Avalon one was $110 for the Tridon and $160 for the Toyota one.

Mind you, I was only looking at ones with M16 thread and had to be low protrusion into the rad tank due to the rad design, so that may have had siome influence on cost.

Cheers

Michael B

[bbaacchhyy]

Below are some numbers as promised


As discussed yesterday, here is a bunch of info on VY Cooling fan control.


Inst. Cluster "Hot Chime" at 118 degC

VY V6 A/C Clutch: "Cut Out" 119
"Cut In" 115

VY V6 Rad Fan Temps: "Low Fan" ON= 104 OFF= 99.5
"High Fan" ON= 107 OFF= 103

VY V6 Thermostat Temps: "Nominal" 91 degC
"Fully Open" 104 degC

And now, here is a cct for high low fan speed setups that has been modified to suit mechanical switches. It was used by Ford for their bosch fans up to BA, and similar to VE.



Some other comments from the guy ;

It requires 3 relays in total, I've shown the P/N's for Holden VY/VZ fan relays which are well suited to fan motor loads. You need good quality high current relays, terminals & cable for cooling fans as they suck a lot of current (typically 20 amps per motor) & can burn wires/terminals or loose fan performance due to voltage drop. Also, you often need to upgrade your Alternator when you fit Electric Cooling Fans, people usually overlook this. Additionally, make sure that there is absolutely no electrical connection to the coolant circuit through your fan wiring as this can cause severe corrosion of the cooling system parts. Basically, this means the temp switches & fan motors must not ground through the radiator or coolant, they should be electrically isolated from the coolant, hoses & radiator.

I have highlighted a particular point in the blub above, as it was not something that I had thought about, but will make sure that I will do it. Fortuneatley, the thermofan switch that I got does not earth with the switch body, so a bit of good luck there.

Any further input from the other knowledgable people out there ?

Cheers

Michael B

[bbaacchhyy]

Below are some numbers as promised


As discussed yesterday, here is a bunch of info on VY Cooling fan control.


Inst. Cluster "Hot Chime" at 118 degC

VY V6 A/C Clutch: "Cut Out" 119
"Cut In" 115

VY V6 Rad Fan Temps: "Low Fan" ON= 104 OFF= 99.5
"High Fan" ON= 107 OFF= 103

VY V6 Thermostat Temps: "Nominal" 91 degC
"Fully Open" 104 degC

And now, here is a cct for high low fan speed setups that has been modified to suit mechanical switches. It was used by Ford for their bosch fans up to BA, and similar to VE.



Some other comments from the guy ;

It requires 3 relays in total, I've shown the P/N's for Holden VY/VZ fan relays which are well suited to fan motor loads. You need good quality high current relays, terminals & cable for cooling fans as they suck a lot of current (typically 20 amps per motor) & can burn wires/terminals or loose fan performance due to voltage drop. Also, you often need to upgrade your Alternator when you fit Electric Cooling Fans, people usually overlook this. Additionally, make sure that there is absolutely no electrical connection to the coolant circuit through your fan wiring as this can cause severe corrosion of the cooling system parts. Basically, this means the temp switches & fan motors must not ground through the radiator or coolant, they should be electrically isolated from the coolant, hoses & radiator.

I have highlighted a particular point in the blub above, as it was not something that I had thought about, but will make sure that I will do it. Fortuneatley, the thermofan switch that I got does not earth with the switch body, so a bit of good luck there.

Any further input from the other knowledgable people out there ?

Cheers

Michael B

[Cuzzo]

Sorry to bring this up but should this be in FAQ?

[The Witzl]

it's already in the FAQ iirc, but not with the extra posts that have been made here.

I'd love to do some topic merging, but need some improvements to the front end moderating controls first

[Robbos_Toyotas]

you also need to mention, in the setup, you need two different sorts of 5 pin relays, a dual way 87, and a single circuit 87.

[ProjectSleeper]

If I can chime in and say that on my 2JZ (running twin 14" thermos) I am running twin relays that are switched by the Jaycar "Universal Voltage Switch" I get the signal from the Gauge Temp probe and have them turn on and off based on the signal (voltage) recieved from the factory probe. I also run a tiny led on the dash that illuminates when they are running so I can tell (as they are very quiet and almost impossible to tell once the engine is running...

No need for a "over-ride" switch as I can easily switch them on at the relays if there is any problems with them not turning on..

Jaycar link...
http://www.jaycar.com.au/productView...=&SUBCATID=347

[Tom86]

I just wired up my Thermo on the weekend. The Witzl diagram would have save me alot of time . Anyway I ended up using a mechanical switch with copper probe, doesn't look as neat but does the job and I can set the fan to come on anywhere between 40-120 degrees.

What would be a good switch on temp for a stock 4agze? I currently have mine set at 80degrees.