A great little mod here by Anthony that uses one of the dial on off switches and the led on the heater control panel for what is normally for heated seats which many dont have.

In summer one of my two cooling fans died. While I waited for the new fan to arrive I decided to fit a fan override switch to give the one remaining fan a head start cooling me down in traffic.
 
I didn't like the idea of using the dash light switch by the left knee as I still use this for the dash lights. On a previous occasion I've had the centre console out and noticed all four rotary dials in the heater unit come with on / off switches built in. I thought I'd be clever and try use on of these for my fan override switch.

 
I located the green/white wire into the fuse box which is grounded by the otter switch when on. I connected a long wire to this and a 2nd long wire to an earth point (I used the earth in the green connector block as described in the mod-wise hot start kit fitting guide).
 
I decided to use the on / off switch at the bottom right which is normally used for the heated seats. There is a LED sitting next to it which was conveniently already connected to a +ve rail via an appropriate resistor, so all you need to do is ground the other side of the LED and it will light up. I wired up the switch as pictured with one leg going to the earth and one going to the otter switch and a pad on the PCB via a small rectifier diode. I used the diode as I also have a fan run on timer installed and didn't want the otter switch being grounded via the PCB when the ignition is off.

I also cable tied the wires to the switches for some mechanical strength.

Now everything works as it should. With the 2nd fan now replaced I never have any overheating problems and never really need the override switch, but I do like monitoring when the otter switch turns on and off via the LED.

Anthony Mathers ( kbear )