Hello everyone!
I am looking to add a fan toggle switch to an '05 S4R to turn the fans on at will - I have read some conflicting information about how to wire this up. Does anyone have some input?
Cheers,
Adam
The fans are controlled by the ECU.
Do you want to have total control (and total responsibility) of the fans?
Or do you want to be able to have the ECU turn 'em on when it wants to, and you have the ability to turn 'em on too?
Quote from: Speeddog on July 19, 2011, 02:37:20 PM
The fans are controlled by the ECU.
Do you want to have total control (and total responsibility) of the fans?
Or do you want to be able to have the ECU turn 'em on when it wants to, and you have the ability to turn 'em on too?
The latter, so they can be turned on at will :)
Cheers,
Adam
Tell "Your Friend" that if he rides faster, the increased airflow over the engine will keep it cooler.
Or just ride his air-cooled bike.
Problem solved.
;D
Quote from: Bick on July 19, 2011, 07:49:26 PM
Tell "Your Friend" that if he rides faster, the increased airflow over the engine will keep it cooler.
Or just ride his air-cooled bike.
Problem solved.
;D
[laugh] [laugh] [laugh]
Cheers,
Adam
The above reply will work - up to a point - on my bike it caused a couple of funny things to happen.
What you have before any changes - The fans are connected directly to the battery via a 7.5 amp fuse - there is no fan relay - the UCU switches the fans to earth after receiving a signal from the temp sensor.
So - it seems the simple way to turn the fans on manually is to just run a lead parallel to the fans earth wire and ground it through a swtch.
My concern before I did this was protecting the ECU - I didnt know what would happen to the ECU if it detected the fans had been earthed namually - would it put up a Check ebgine light.
The first thing I did was ask on another Ducati Monster forum and got no replies at all.
I ended up contacting a person named "Decosse" on a Triumph forum who fixes all our Triumph electrical problems.
His suggestion was that simply earthing the fans through a switch should be okay - but if I wanted to "hide" the switch from the ECU I should install a diode. on the earth wire between the ECU and the fan.
I did this on the LH fan only to start with - with ign off only the LH fan comes on when using the manual switch - but - with the ignition on both fans turn on - I became concerned at this stage - I got the bike up to temp and both fans switch on and off austomatically - so at this stage (by accident) I have what i need - but why does the other fan switch on as well.
I contacted "Decosse" and he cant explain it - I contacted an Auto Electrician and he suggested the ECU is probably smart enough to detect the manual switch (even though I have the Diode fitted) and the ECU is going into some sort of protection mode and switching both fans on. ...to be continued...
Continued from previous post .....
So I went ahead and connected the RH fan to the switch including fitting the diode (to protect the ECU) - what happened then was the fans turn on manaully (the same as before) but - when I got the bike up to temp the fans switched on automatically but would not switch off at all. I contacted my Auto Electrician again and his best suggestion is the same as before except now the ECU has stepped up its thinking to protect the bike even more by keeping the fans on all the time. He also suggested the ECU may have logged an error code but thankfully not shown a Check engine Light.
I disconnected the connection including the diode to the second fan and I am back to having what I want ( still with the mystery of why does the secong fan turn on).
If you go ahead and just parallel a wire through a switch - could you let me know the results - dont forget to test the auto switching on and off.
By the way - my 05 S4R is completly standard (wiring wise).
Hope my info helps you a bit - Let the Good Times Roll - Ray.
Some SBK's have the fans controlled directly by the thermosensor switch.
They can use the lower-temp thermosensor switch.
Fans on the S4R are controlled directly by the ECU.
They cannot use the lower-temp thermosensor switch.
Thanks everyone ... SpeedDog, any consensus on the "right" way to do this? [Dolph]
Cheers,
Adam
Carbon14 - yes, you are probably right - except there is a bit of info I omiited that might be the cause.
Before I started I disconnected the fan wiring plug ,which is about 6 inches from the fans - multimeter - I has 12 odd volts at the blue wire (as you would expect) and .25 (1/4) volt at the black earth leads (both exactly the same) - my thinking here is that it should have shown "open circuit" and when the temp sensor sends its signal to the ECU the earth lead simply makes a connection to earth - so it seems its not that simple.
The idea of the diode was to make the switch invisible to the manual switch - just in case the ECU is smart enough to detect a "short" to earth in the fan wiring.
Our best guess is that this is actually whats happening and the 1/4 volt on the earth lead is there for a reason like this - there is a voltage difference across the diode - the end result is the second fan turns on even though its not wired up to the manual switch at all.
Another way I am thinking about this - the earth wire is not actually a "earth" wire - its just a return wire that forms part of the circuit that includes the temperature sender - maybe the temp sender has a voltage applied to it which changes (read resistance) as the temp changes - it uses this to provide the dash temp readout and eventually the ECU senses the change in resistance and turns the fans on.
I am interested in any findings on this - Let the Good Times Roll - Ray.
Not to be a picky bastard, but we really ought not discuss how to do the fan mod on an early SBK (at least in *this* thread).
It's a totally different system and we're confusing the issue at hand; how the OP can manually control his '05 S4R fans.
The '05 S4R has two temperature sensors, one which is hooked to the gauge temp display, the other is hooked to the ECU.
So changing sensors will either fool the display, or the ECU... neither of which is a good plan.
AFAIK, the fans are supplied with 12V+, and the ECU controls the ground/earth, as has been described by LTGTR.
I hesitate to ground wires that lead into the ECU, even if that's all that the ECU does with them.
ECU's are a rather expensive part to experiment with.
Perhaps someone more 'sparky' than I can weigh in on how to get the diode scheme to work.
Speeddog - yes, we do need someone who understands the logic of the ECU .
The original OP hasnt got any clear instruction so far - I wish I could help more.
Here is a summary of where i'm at - split up into good and bad.
Good:
My current manual switch and diode mod, for the LH fan, works - it turns both fans on manually and they still turn on and off austomatically.
I dont have a "check engine light" - my bike still runs perfectly.
Bad:
Why does the RH fan turn on even though its not connected to the manual switch ( only the LH fan is connected to the switch and also has the diode in the circuit beween the switch and the ECU).
Why dont the fans turn off automatically if I complete the modification to the RH fan i.e. connect it to the manual switch and install a diode between it and the ECU). Purley guessing now - I may have an error code logged in my ECU.
To Drdesmodemici - if our bikes are identical and you carry out the same modification you will have what I have - I guess its up to you from this point.