How to fit thermo fan bypass switch

[Immortality]

hi all,when i brought my vs everytime ya turn the key to to start the cooling fan is always flat out,when i popped the bonnet & looked in the fuse area i seen a red cord going from the fan to the fuse for the heater fan,instead of having the fan flat out all time can i just unhook it and put a variable speed switch so its not flat out,and have it on low n high like its soppose to do already by its self.if i ran the red wire to the swtich and ground it to something and just use it when it gets hot,or do i have to tap into the fan bypass wire like it said in this how to ???

sorry mate, you ahve lost me a little here? to clarify, we are talking about the thermo fan and not the fan for the aircon inside the car?

the low speed/ high speed fuction onthe VS thermo works through 2 relays so a variable speed pot is not necessary.

the thermo fan will run when you start the car if the aircon is on. this is normal. if the thermo fan is running constantly (even without the aircon on) then you need to find out why. possibly try changing the relay. it maybe stuck ON

 

[ashbox]

just a bit of info, daron tried to fit one of these to my vz and there was no luck its a similar setup with plugs and everything but we seem to think the ecu controls it a fair bit more than what the earlier models do. going to research this further.

 

[HUMBLZ]

any news for vz alloytec yet?

 

[Pimpn1]

very good write up, just done today works a treat cheers to the OP

 

[purrVN]

hey mate, when i bought my car it came with a switch already fitted, however it hadn't yet been hooked up. i am yet to see the fan work on its own accord, even with the air con switched on, so after reading this thread, i decided to connect up the switch and hope for the best. When you first switch it on, the fan comes on and stays on no problem, however, when you switch it off and try to switch it on again, it will just give a bit of a kick and not start the fan going, and continues to do this every time you ty to switch it back on until you trn the ignition off/pull the relay or leave it for a while. I've tried two fans, i disconnected it from the computer and just had the wire earthed, i've swapped the relay and i've shorted across the main power terminals of the relay to make sure it was getting power and the only time i didnt have the problem was when i shorted the relay terminals across. do you know why this would be happening? is this normal? oh and even when i have the switch in the ON position and the fan ISN'T working, the led in the switch is on so its still getting power... PLEASE HELP!!! thanks man

 

[Immortality]

because the fan worked when putting a jumper wire (shorting) between the 2 main power treminals on the relay base and the fan worked would suggest that all the power wiring from the fuse > relay base > thermo Fan is fine and working. since you also tried another relay with no joy it would suggest that there is a wiring fault in the wiring from the ecu to relay.

try fitting a relay (a known good one) and then shorting out the wire (to ground) that comes from the ecu at the base of the relay. you can remove the relay base from the main fuse panel using a small flat screw driver down the front of the relay base where it fits into the main holder, push the tab in towards the relay base and then pull it up. you can also check the wiring visually while you have it out

 

[Peter89]

have completely bypassed the thermo on my vn, runs so cool now.

 

[kalboy]

vs commordere thermofanbypasswiring

can some one please tell me which colour wire it is on the vs model has i have put the circuit tester on the blue and white wire with the key turned full on and get no power.

 

[Cheap6]

This should help:

http://www.memcals.com/pdf/VSV6 Auto Wiring Diagram.pdf

You should have battery voltage at the wire at the PCM or BCM until the fan is switched 'on' (i.e. the wire is earthed).

 

[DMG_90_No.18]

I agree with Commsirac. Fans do work over 100km/h. I'm so sick of reading crap about they don't work over 40km/h. If you have a manual switch you will find out for yourself so read on because below I state how to wire up the fans so you can have 2 settings on the one switch. Normal operation as per the ECU and a manual trigger to cool it down when you need it.

The design of the fan and shroud will determine at what speed they will work at and at much higher speeds then the standard straight over the top and side shrouds you get on the VN commodore where the air goes straight through and is not designed for the air to circulate around the radiator. With the Shroud I have it has the same measurements as thee radiator but is 75mm back from the radiator which means the air comes in but it just does not just flow through and disappear, with this shroud the air is held a little longer for efficiently and with this method it allows for a greater rear surface area that the air can travel over and therefore cools the radiator quicker and more efficiently, it exits before the air is to hot to reverse the effect.
Pressure helps this shroud and fan combo work. Larger diameter fans do the same which is to increase the follow over the rear surface area, Shrouds will control the exit direction of the air making it closer to the middle rear of the radiator which groups the flow making it quicker because of increased pressure. I have seen full aluminium shrouds but mine is plastic plus with 2 fans like mine you get an increased rotation rate, same goes for bloody large fans.

***Wiring up a Twin Thermo Fan
I own a VN commodore. The thermo fan wiring from the cars loom is 1 Black and 1 Orange/Blue wire. Now I used a switch which has two positions UPPER/LOWER and placed it next to the A/C switch for ease of reaching. My aim was to have the fan operate under normal conditions so if I turn the Air conditioner on the fan automatically starts and will still operate with the thermostat. Normal conditions we will call it The LOWER switch position.
The UPPER switch position is to manually operate the fans. The VN heats up very fast in traffic or giving it a bit of juice.
If you wish to add a light I would just use the oval switches with tiny LEDs in them.

You need wire, 3 different colours would be great or make them with number/letter stickers and a switch. The switch requires 3 electrical connections. The wires we will number 1, 2 and C.


The fan comes with two BLUE wires and two BLACK wires.
• As per below the Black wire from the cars loom should be attached to the fans black wires.
• The Orange/blue wire from the Cars loom should have another wire added to it and this goes in the position 1 location.
• The Blue wires from the THERMO FANS are attached to another wire you have supplied and it goes in the position of C location.
• The other supplied wire is attached to the Battery and is attached to the position 2 location.