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999 fan running all the time.

Discussion in 'Technical Help' started by 900streetfighter, Jun 4, 2013.

  1. Probably my fault when I messed around fitting an ecu behind the battery box last week. The wires to the thermostat in the coolant manifold have worn through with the l/h fan blades touching them. They have probably shorted together at some stage. I've cut and soldered the wires and heatshrinked them but the l/h fan is running when the ignition is on when the bike is cold. Also yellow management light on dash is lit. I tried it with the stat disconnected and the fan still runs. I'm hoping I've fkd a relay and not the ecu. No other wires are damaged and the bike runs ok. Anyone had a similar prob?

    Cheers, Keith.
     
  2. Sounds like you've spiked the ECU. All is not lost though. Find the diagnostic connector, it's a 3 way superseal connector to the left side of the battery box. It's held in place with a rubber fixing and will have a protective cover over it. The 3 way connector has two wires into it. What would be the middle wire in the connector is an earth wire. You need to tap into this wire and run a length of wire from it to the -ve terminal of the battery. This will stop the fans and also stop the MIL on the dash.

    749_999 diagnostic.jpg

    749_999 diagnostic.jpg
     
  3. OK that sounds easy. Will try that tomorrow. So I connect centre to -ve then turn ignition on for few secs, turn off, disconnect. Job Done, Yes? Many thanks. Keith.
     
  4. Good skills sir!!
     
  5. You have to leave the wire connected. You have had a +ve spike down the -ve side of the ECU.

    The mod will cure the problem, we see this on the Ducatidiag site when people invert the power leads on the diagnostic connections.

    The alternative is a new ECU.
     
  6. That was clever of me then. I'll be banning myself from toolbox after this. Will a reflash sort it properly?
     
  7. Unfortunately no. However, you can quite happily run the bike with your current ECU once the mod is done.

    This is distance diagnosis but the symptoms you describe mirror those caused by a polarity inversion to the ECU.

    Shit happens, but hopefully we can fix it :upyeah:
     
  8. Ok, many thanks for your help. Will post result tonight.
     
  9. Chris, Bike is all ok now. I hot wired it from socket to -ve as you advised and it was still the same. So I was about to see if the RH fan kicked in at 103 as it should with the intension of wiring both fans into one set of wires when I noticed I'd unplugged the RH fan. When I plugged it back in it all worked as it should without the 'hot wire'. Very Happy:smile: Many thanks again for your help. Cheers, Keith.
     
    #9 900streetfighter, Jun 5, 2013
    Last edited: Jun 5, 2013
  10. I'll add it to the memory bank :upyeah:
     
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