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Discussion Starter #1
Hi, my cooling fan circuit conked out a week ago. I've check the fuse and looking at manual for 2006 910s and can't find the fan relay. It's not obvious and the manual refers to p.38 but there's nothing there about a relay. Help, plz, going nuts

cheers, Claudio
 

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Discussion Starter #3
Claudio, I'm pretty sure the SPU controls the fan on the Brutale, meaning it's a relay inside the SPU. I might be wrong, which drawing are you looking at.
manual from ur teamdouble3racing site called "mv-agusta-brutale910_chassismanual.pdf" total 396pp. I'm looking at manual on absolute page ref. 164 (E5). On p.201 (E44) says check fan relay on right side of motorbike as indicated on p.38???

I've done as instructions on p164 and bridged the temperature sensor plug marked M and the fan doesn't kick in. I'm not getting voltage on either side of the fan fuse 7 with ignition ON but motor not running (I've checked and replaced the fuse). I've checked the fan motor with ohmmeter and seeing about .2ohm. I've yet to put 12V on it to test the motor to double check
 

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Yup, sounds right, or wrong for that matter.
Yes the fan should have kicked in, and no, there is no relay outside the SPU.

If you look at the wiring diagram, follow the lines indicating the fan wires, they go straight to the SPU.
Run two wires from your battery to the fan to do a quick test on that also.

Where are these smart arse Brutale riders when you need them ?
 

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Discussion Starter #5
put 12v direct to the fan and it works fine. I've been pouring over the electrical diagram along with an engineer mate of mine and we can't get our heads around it as far as the fan circuit. In the electrical diag on p163 (E5) one side of the fan goes to common ground and the other heads off to the right then up to a connection 10? on what looks like a bus perhaps the fuse panel. We can't figure out how this relates to fuse 7, which is supposed to be the fan fuse. How this ties up to the fan relay (whereever that is?) and the Power unit is beyond me. I must be missing something.
Any help appreciated, cheers Claudio
 

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No Claudio, the big square thing you see with all the connections is an SPU(Control box). In there is various relays which control various fuctions on the bike. There is no seperate relay for the fan. The fuse feed goes to and then through the SPU to feed the fan.
 

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Discussion Starter #7
Hi Donsy

ah, ok. So, back to my original problem with the fan not coming on when temp is over 94º. Where do I backtrack to find out where the circuit is broken? I assume that at ambient temps there's no voltage coming out of the SPU. That might suggest the coolant temp sensor but I am getting a temp reading on the dashboard panel. If the fan fuse feed is between the battery and the SPU, I should see 12v at the fuse with the ignition ON but I'm not. Is this right?

thanks in advance, C
 

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You have 2 temp probes (Item 22 and 36), one on the radiator which feeds the display, one on the engine which feeds the ECU. The ECU then tell's the relay inside the SPU to start the fan. Swap the connectors on the 2 temp probes and see if there is still a display reading.
Check this first mate.
 

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Discussion Starter #9
will do tomorrow, thx donsy
 

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Forgive my ignorance, but is the wiring that different to an 06 F4? I encountered same problem and had to replace the relay and fix a broken wire.
 

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Discussion Starter #12
Donsy, like u suggested, I've been slowly getting my head around the various electrical diagrams and finally starting to make some sense. In the function diagram marked "CPU" at Sect E, p.22, the battery is passed through the contacts of the General Relay to fuse 7 then on through "Utility 05"(is this the fan relay?) and connects the engine temp sensor to the fan motor.
As mentioned earlier, I'm not getting 12v at the fuse 7 (fan) with ignition ON and safety switch to RUN. This points either to the General Relay not actuating or a dodgy wire. Don't know for sure, but I'd assume that if it were the General Relay, then a lot of other things wouldn't be working yet the motor was runnning OK and all other things appeared to be functioning normally. I've presently got the tank off because I'm fixing the fuel pump so I can't run the motor at the moment. I'm going interstate shortly so don't have much time presently but any idea where I can find the General Relay? I'm supposing its somewhere inside the CPU/SPU unit housing?

MaximoMarc, u replaced the relay. Do u mean the fan relay and can tell me where it is on ur bike?

cheers, Claudio
 

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Hhhmm

You're confusing the crap out of me now mate.
Ignore the F4 comment - you're wiring is completely different, believe me, I made my own F4 wiring loom.

On both Brutale 910 2006 drawings I have here, Utility 5 is the diagnostic plug?

Time for pictures.
 

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no fan?

Claudio;

like Donsy said, switch the plugs on the 2 temp sending units

if the one in the radiator is good and the one in the motor is bad the fan won't work

the motor must be running and be over the normal fan switching temp

if when you switch the plugs and have a hot running motor and the fan comes on its a bad temp sender and you won't get a dash display

if it still doesn't work with the 'M' plug on the sender in the radiator its the SPU

the temp sensor in the radiator is good.....we don't know about the one in the motor

is the back of your SPU blue?
 

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You can also just unplug the fan sensor. The SPU will see high resistance (open circuit) which equates as high temperature and turn on the fan. If it doesn't then the SPU is probably bad. Very common for the older units.

like Noel asked, is the back blue?
 

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Discussion Starter #18
Donsy, thx for those 2 links on SPUs. Very informative. Noel, my SPU back is black. I've attached a pic of my SPU and there's nothing obviously cooked. I'll need to do some checking for continuity at contacts etc.

Another thing that's niggling me: the "CPU Function diagram" on p.E22 shows the left-hand side of fan fuse F7 going up to the contacts of the General Relay and drawn as a solenoid actuated by the ignition switch. Anybody know for sure if this is a discrete analog relay outside of the SPU or yet another digital component inside the SPU and, if the former, where is it? Likewise, the companion Power Relay just below it in the diag?

esq'z me, thx for the tip to unplug the radiator temp sensor (open circuit). I tried bridging the engine temp sensor again with ignition ON/starter RUN and blow me down the fan came ON!

Now looking less like the SPU and I'll go back and check the two sensors as previously advised

thnx for staying with me on this merry-go-round

cheers, Claudio
 

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Discussion Starter #19
Claudio;

like Donsy said, switch the plugs on the 2 temp sending units

if the one in the radiator is good and the one in the motor is bad the fan won't work

...

the temp sensor in the radiator is good.....we don't know about the one in the motor

is the back of your SPU blue?
Back on deck and firstly tnx to all for the feedback including esq'z me via PMs. I checked my SPU and it's the latest type with black back. :drummer: Stoked up the bike last night and the fan now works normally.

I got a new temp sensor and checked the resistance at ambient temp. Checked the radiator coolant temp sensor and the engine temp sensor resistances and they all showed similar readings. As I was doing this I noticed I was getting intermittent readings with my ohmmeter probes and decided to clean both the male/female connector pins in the plugs (with a Siemens contact cleaning tool used for Siemens cross-bar telephone exchange relay contacts from the 60s). I also installed a manual switch to turn the fan on directly.

The fan now works normally. The radiator temp sensor has been working and shows correct temp. I assume the fix was that the engine temp sensor contacts were tarnished and caused open circuit (equivalent to SPU interpreting "Low Temperature") and therefore was preventing the fan from kicking in

many thanks, cheers Claudio :hitit:
 
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