Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Trouble shooting a radiator fan

Discussion in 'Technical and Troubleshooting Torque' started by UMGAWA, Feb 28, 2009.

  1. Ok here's the details, VTR250 2007 model

    Here's the dealio, Bike will have a high mid to low low temp range after a long/hard ride but i never hear or see the fan engage whilst idiling whilst at these temps.
    Have read the manual and it seems to be the right range for the fan to engage yet nothing.

    The only thing i could think of was when i accidently ran the battery (oops) and jump started the bike but i checked the fuses noted in the manual and everything is in order and checked all the plugs leading to the fan..

    My only conclusion is that the sensor is fubar'd

    Anyone with some advice?
  2. multi-meter, check for current. Find resistance specs and check ohms on sensor ?
  3. Hold fast (2000 rpms) for a few minutes after a ride and let her heat up
    a bit, if fan doesn't come on then run a wire direct from the battery to
    the positive + of the fan, fan should run, if it does then temp sensor will
    be suspect. either replace the sensor or fit a manual switch to the fan.

    My 600's fan only came on at traffic lights on the 46 deg. day we had recently, if the cooling system is ok you will rarely hear the fan.
  4. Remove the wire from the pick-up on the radiator and ground it to earth. If the fan doesn't start, then you have either a blown fan fuse, or a blown fan motor. (Pray it's the fuse, they're cheaper!!).
  5. I guess that could be a possibility the bike rarely (if ever) gets a "hot" temp reading.

    Maybe I'm just looking into it too much.. but i'll give that a try.
  6. The temp gauge is only an indicator and nothing scientific.
    My Bandit fan had never come on and I don’t think our ZZR fan has either.

    Do as others have suggested except for reving for a couple of mins as a test but the gauge is not gospel :wink:
  7. To test the fan you can disconnect the lead from the thermoswitch and ground it, the fan should come on. If it doesn't then there is either a problem with the fan or a blown fuse.

    If the fan works then you can test the thermoswitch with a multimeter, it should allow current to pass when it gets up to temperature.

    I recently had the same problem with my spada and it turned out that the fan was just disconnected and all the components were working. So i simply had to reconnect it to fix the problem, but I doubt that this is a common cause of fan problems.
  8. I have a '99 VTR250 and in the 9 months of ownership have only heard the fan come on once (scared the crap out of me :LOL:). I think given the engines efficient cooling abilities, it would take a very hot day for the fan to come on.
  9. You'll go nowhere fast if you don't learn to read the other posts in a thread before you post an identical answer :roll:.
  10. What do you mean Paul?
  11. look up; user "nowhere fast" just about quoted my earlier post :LOL: It was a poor pun :).
  12. Oh lol. I thought it was directed at me. In that case, carry on, nothing to see here :LOL:
  13. "Trouble shooting a radiator fan"

    I don't see what the problem is, if its not working it can't be running very fast.
    Maybe your aim is good, but you're just unlucky and the rounds are passing between the blades.
  14. I dunno if these things have relays, but I have encountered bad batches of relays between similar model cars that stuck open, sure it wasnt bikes but relays are all the same, just an idea.
  15. :p
    I was thinking the same thing. "Get a bigger gun" or something else lame like that! :LOL:
  16. Ditto, I was thinking use a shotgun as it's hard to miss with one of them.