Will my fan wanring light...
adithorp - 16/5/13 at 03:12 PM
...flash when it shouldn't?
Following on from THIS thread.I never managed to get the coolant level light to
work so I abandoned it. That left me with an unused dash LED.
So today, I wired it to my fan override switch. It now tells me that the fan is on; Both when the ECU switches it (handy as overheat warning) and when
the override is on (handy, as I often forget to switch it off).
Now when I swich the fan off, the LED flashes for a few seconds after (untill the fan stops rotatinng). I suspect the motor is acting as a dynomo and
back feeding...
Is it going to come on when moving and the wind pushes the fan round? 
steve m - 16/5/13 at 03:22 PM
"Is it going to come on when moving and the wind pushes the fan round? "
Mine doesnt, and only comes on when the fan is on, but im using a normal bulb, not led
Dingz - 16/5/13 at 06:47 PM
My 'normal' bulb has come on in the past when the fan has been acting as a dynamo, I think I should put a diode in the line.
Neadles - 16/5/13 at 06:54 PM
As said a 'flyback' back diode in parallel with the fan in reverse polarity or in series to the LED will probably work.
britishtrident - 16/5/13 at 07:38 PM
Bin the switch and just let the ECU get on with the job of controlling the fan.
loggyboy - 16/5/13 at 09:26 PM
Use a relay.
adithorp - 16/5/13 at 10:01 PM
quote:
Originally posted by britishtrident
Bin the switch and just let the ECU get on with the job of controlling the fan.
ECU switches the fan at 105c and it works fine. However above 95 it gets easy to stall. Come to a hold up on the motorway in summer and the temp
climbs pretty quick and your into stalling territory. Flicking on the fan is just easier.
Similar applies at the end of a session on a track day or after hooning up a mountain pass. Switching on the fan gets a head start on the heat soak
when you stop.
Why can there be 116.67% of votes?
[Edited on 16/5/13 by adithorp]
adithorp - 26/5/13 at 02:57 PM
Drove the car today and the answer is.... 2 (though it'll probably get to 3 pretty soon).
RK - 26/5/13 at 05:20 PM
I don't know why, but my fan switch, wired to put the fan on at XXX temperature (I can't remember where it was set), never worked, so by
putting an override switch and a small LED in series, I turn it on whenever I want, and the light is on when the fan is OFF to warn me. If yours is
controlled by the ECU I would let it do it's thing, as BT says. Mine is one of the wiring mysteries that I cannot be bothered to try to fathom
anymore.