Thermo Fan switch bypass

[BUSTER1]

Can somebody please tell me which wires do you earth out to make the thermo fan come on ,I found the post on vn & vp v6 but I have vs v6 auto and the computer is different
Thanks in advance for any help
Cheers Garry

[hako]

Do you want to do hi or lo speed? - hi is a bit noisy and low is usually OK to keep temps down with hi for the aircon.

[BUSTER1]

hako i would like high speed as the ute gets hot in traffic when I am towing my boat ,also if is on highI will here it and turn it off when I dont need it , thanks for your help mate
Cheers Garry

[hako]

OK - I'll play with it this arvo...from the wiring diagram there is a blue/white tracer wire that goes to the hi speed relay and then to the ECU....so if I short that to earth the fan should come (ign on). I'll try it and take a pix.

[PRAVX II S]

hey mate on the vs commodore your power train control module supplys a earth signal to the fan relay
the colour of this wire is blue/white.
It comes from the PCM.
The location of this wire is F6 on the PCM plug. Or you can go to the harnness near the relay.
Suppy earth. with the ignition on it should work.
Check with a test light or a multimeter to confirm the earth supply of this wire.

[hako]

Well that was a lot easier than I figured....pix will tell the story.
pix 1 is location of blu/whi wire at back of relay (just for info)
pix 2 is where that wire also runs...to an easier location near the top rad hose
pix 3 is the cover removed and wiring exposed - it's the blu/whi one we want to earth
pix 4 is of the blu/whi wire with a pin thru it and wire running to earth (batt negative)...when this wire is connected with engine running the hi speed fan comes on....no bad effects any where else down the line so it appears safe!!!

So. you need to simply run a wire from this blu/whi cable into the cabin to a switch and earth the other side of the switch. Ign must be on for the fan to work.

I'll wire it up properly and do some more pix and then a "how - to"

Hope this helps.

[PRAVX II S]

You could actually find this wire at the PCM.
And is located on the f6 pin.
You don't have to run it through the engine bay mate.
If any one is curious this wire color is the same on the VTs. blue/white

[hako]

You could actually find this wire at the PCM.
And is located on the f6 pin.
You don't have to run it through the engine bay mate.
If any one is curious this wire color is the same on the VTs. blue/white

I considered doing this but figured that I'd have to remove the kick panel to access the ECU and then run a wire across the dash over the heater unit.....so breaking into a wire with easy access and then running a wire thru the bulkhead seemed the simpler option to me. I also prefer not going near the ECU as I figure I'll break it although I must admit it would look a bit tidier.

[immortality]

LOL, this brings back memories.

i'd do it at the PCM, saves running a wire though the firewall.

i though i'd linked wiring diagrams in my How-to for the VS models

the real problem is that they run the VS so bloody HOT to begin with. i'd run a cooler thermostat and reset the on/off temps in the tune to suit. like i did with mine. for towing i'd consider fitting a better radiator. maybe a V8 one and a great big external trans cooler

[hako]

If the engine and cooling system is in good order, the car should never overheat under normal operations. Fitting a cooler thermostat and larger radiator may keep the engine cooler but you sacrifice part of the research design advantages of the Ecotec system ('Emissions Control Optimisation TEChnology).
Most if not all modern engines run at high temperatures to produce more power with less emissions.
But, I'd have to admit that I prefer a cooler running engine.

immortality - do you have the link for the "how-to" you did on wiring the fan ----- that will save me doing one if you've done one already.

[PRAVX II S]

engines have optimum temp
so to cold or to hot is no good for a engine.

[PRAVX II S]

I would put I diode in line on the blue/white wire to protect the PCM of any back feed or short to the PCM
Inside the PCM A transistor supplies the earth to the relay. And if this transistor stops working you could have problems.
It might not happen but I rather be safe then sorry.
up to you bro.

[VXHBD6]

Seems pretty easy, if I ever have to do this ill make sure to read this agian. Cheers.

[hako]

I would put I diode in line on the blue/white wire to protect the PCM of any back feed or short to the PCM
Inside the PCM A transistor supplies the earth to the relay. And if this transistor stops working you could have problems.
It might not happen but I rather be safe then sorry.
up to you bro.

That is a good idea!

[BUSTER1]

hako thanks for the trouble you have gone to ,but I still cannot get the fan to come on ,first up there is no blue/white wire to the fan motor ,there are 4 wires going to it ,[see pict] when I put the test light they show as all negitive ,so I dont know whats going on,the fan works fine comes on with a/c and temp switch
Cheers Garry

[hako]

The blu/whi wire that I show next to the radiator top hose actually goes to the A/C hi/lo pressure switch but it also is the same wire as shown at the back of the relays and also the one that praxIIs talks about at the ECU.
I think the problem lies in the fact you have a ute....and if it's series 1,2 or 3.
It's also possible you have opened the wrong taped cable....look in the same are near the top hose for another taped cable...open it and see if the whi/blu wire is there. The taped cables you need to locate go to the hi/lo A/C pressure switch which is part of the A/C drier.
I prefer not to play with wires near the ECU.

[PRAVX II S]

[QUOTE=BUSTER1;1443640]hako thanks for the trouble you have gone to ,but I still cannot get the fan to come on ,first up there is no blue/white wire to the fan motor ,there are 4 wires going to it ,[see pict] when I put the test light they show as all negitive ,so I dont know whats going on,the fan works fine comes on with a/c and temp switch
Cheers Garry[/QUOTE


The blue/white wire will run from the PCM F6 pin to the high speed relay.
This signal is a earth.
So find the right relay (High Speed) and under the relay holder you will find a Blue/White
wire.
This wire is only to turn the relay on and of. (It Controls The Relay)
It does not go straight to the fan motor.

[VSIIBerlinaL67]

i though high speed mode is when low is already running and it switches on the other motor behind the fan which makes high speed? dunno could be wrong

[Brett_jjj]

On my VS V6 theres only 1 motor on the cooling fan,its a 2 speed motor.It goes to high speed by connecting both the hi and low speed wires both to 12 volts at the same time,and both earths connected to earth at the same time.Theres 4 wires going to the fan motor,2 earth wires which Im pretty sure are black.And theres 2 live wires,one for low speed and the other for high speed.(but not on its own).The low speed wire is Blue/yellow,and the other high speed wire is orange/blue.But what you need to do to be able to manually switch the high fan on and off is go to the relays under the bonnet,and find the "eng fan" relay.Theres a blue/white wire that goes to this relay's socket,thats the wire that has to be earthed out to get the high fan to come on.All that needs to be done is to tap into that blue/white wire,join another wire to it and run the new wire to a switch on the dash or wherever,then run another wire from the other side of the switch to a good earth.

[Jaym]

Sorry to bring up an old thread but I just went to do this to our vs. turns out the wire blue / white is live.
Tested it near ac pressure switch an relay and it has 12 volts

Any ideas?

Cheers
Jay