failed fan motor

[Greg May]

Hi RM, you fan motor is a DC motor so it will have brushes in it, whether you can rebuild it or not I'm not sure but if it turns free there is something you can try, if it works I wouldn't recommend it as a long time cure especially if you are in a lot of traffic in a hot climate. Since you say that if you spin the motor it will continue to run on it's own and you don't mention that it runs then hesitatesthen runs again which would indicate a shorted segment/segments in the fans armature or a shorted coil so lets go from there. This kind of motor is called series would, if the winding goes open, it never runs again, if the windings short it dies very quickly or it's supply fuse blows from excess current. This is where it gets real scientific, to get a possible temporary repair, unplug the fan, remove it from the bike and with a suitable (read small) hammer, tap (use discretion), on the body of the fan motor. Not on the shaft or the blades and not hard enough to damage the body. If you are lucky you have a brush stuck in it's holder and the taps will free them up enough to make contact with the commutator at least for now. If your not lucky the brushes are worn out to the point that they don't properly contact the comm. By spinning the fan by hand you are compensating for the bad contact that the brushes are making with the comm allowing the fan to spin, it's also because of that bad contact that the fan won't spin up to speed. If you could see inside the motor while it was running you would probably see a nice blue trail of sparks on the comm surface as the armature rotated. Because of this arcing even if you get the brushes freed up so the fan will start as it should on it's own it still maynot run up to speed because of the brush carbon that has been deposited on the comm surface......Have a great evening......Greg RM wrote: The fan spins very slowly and needs some help getting started. The bushings are OK -- The fan spins easily. It just doesn't have any torque. It'll do nothing until you rotate the blades to a certain point. I think a winding has burned out. RM On Mon, 11 Feb 2008 12:45:32 -0800 (PST), "Walter Mitty" said: Are you sure it is the fan motor and not something else like the relay? There are some on eBay as we speak. --------------------------------- Instant message from any web browser! Try the new Yahoo! Canada Messenger for the Web BETA [Non-text portions of this message have been removed]