Fan Override Switch Using Fog Light Button
#1
Posted 24 June 2018 - 01:33 PM
I've recently done my 1st track day and as adviced by members here that it is a good idea to have a fan override switch to control temps when pulling into the pits.
On track I was getting 89-91 degrees and then it quickly crept up when driving to the pits 94-95 as I reached the garage.
During my prep to get the car ready for track I fitted brake ducts, removing my fog lights, hence having a spare switch available.
Start by removing the center console/gear stick cover. There are 2 bolts at the bottom either side in line with the gear stick, it should lift up about 8" or so to allow you to get at the loom. Remove some of the black tape, covering the individual wires (big bunch of 20 or so wires) . Locate the blue and grey wire. Strip a portion of the insulation out of this blue & grey(stripe) wire and test. I tested by putting ignition on and putting a screwdriver from the newly exposed wire to the metal on the gear stick and you should here it go on. Then remove keys again (I don't know if ign needs to be on? I just presumed it did)
Then route a cable (a small cable size is fine, speaker cable size) from here to the fog light. As mine is carpeted I fed it towards the front, under the dash and passed the black plastic sill guard and in to the right of the switch panel.
Be warned there's not much room and it's difficult to work on your back to feed the wire through. Make sure you cable tie the new cable up. Don't bother trying to feed the cable up through the bottom of the dash, as there is no way in, just bring it in to the right of the light panel.
If it's not carpeted then I'm sure you could route the cable backwards behind drivers seat and under the sill cover.
Remove the cover around the light panel (mine was just velcroed on) also remove the small panel to the right of this (2 screws), then one screw on the sill cover to allow you lift this up enough to feed the wire in.
Then pull the panel off that the 5 light switches sit in (4 clips, 2 top and 2 bot)
Remove the block on the back of the front fog light switch. Then cut all the wires off (about 2"from block) apart from the black one (this is ground and needed). Strip the blue wire on the connector side and wire your new wire to this. Solder both ends, fit switch, put ign on and test. Then tape up the new connections and tape up the ones you've cut just incase anything shorts.
Put everything back and hey presto, when you put on the front fog lights the fan will come on (the light on the switch even works aswell)
You are basically putting the wire near the gear stick to ground via the switch. This will activate a relay, hence not needing a thick wire.
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#2
Posted 25 June 2018 - 05:51 AM
Good guide, one very small correction is that you don't need the ignition on to test / run the fan by putting the Blue Grey wire to ground. Relay works from a permanent live rather than a switched live.
#3
Posted 25 June 2018 - 07:04 AM
#4
Posted 25 June 2018 - 02:05 PM
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#5
Posted 07 July 2018 - 11:30 AM
#6
Posted 07 July 2018 - 05:04 PM
Fag lighter?
#7
Posted 07 July 2018 - 08:01 PM
#8
Posted 10 July 2018 - 05:56 AM
Just an add on if anyone did do the fan switch this way,, you will need to solder the red /white cable on the switch to the black. As there is too much resistance where it lights the switch lamp and Disney always upstate the fan. If you wire the red/white to black it will work everytime. (see photo)
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#9
Posted 10 July 2018 - 07:53 PM
Good option to have regardless of switch method.
#10
Posted 19 October 2018 - 09:44 AM
Auto Electricians ?? Could do with some help guys. I decided to fit a fan override switch to the centre console ( handbrake cover ) and bought a toggle switch from Radio World and find it has 4 connectors. When I cut the blue/ grey I will have two wires and a new piece to ground on handbrake fastening makes three. What goes where on the switch ? The four terminals are marked 1&2, 3& symbol( which looks like an anchor) , 4&5, and 6. Your help would be much appreciated.
#11
Posted 19 October 2018 - 01:09 PM
I'd expect that it is effectively two independent circuits each with an open and closed state, toggled by the same switch? Got a multimeter?
#12
Posted 19 October 2018 - 01:15 PM
To retain the functionality of the ECU trigger, maintain continuity of the Blue/Grey wire, but give that wire an additional feed that passes to one side of the switch, and then wire from the other side of the switch goes to ground.
#13
Posted 20 October 2018 - 07:39 AM
To retain the functionality of the ECU trigger, maintain continuity of the Blue/Grey wire, but give that wire an additional feed that passes to one side of the switch, and then wire from the other side of the switch goes to ground.
That makes sense and maintaining continuity is the key to it becoming clariified in my mind . Thanks for your time.
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