Radiator fan testing

[JoelG]

Ok, so I've read many threads that are related. It's the standard situation: I dropped the bike off-road on the left side. It pushed the fan mount into the radiator and bent the bottom of the rad. Fan was pushed against the rad so it wouldn't start.

I've bent the fan mount out, and now the fan kinda works... if I hit temp, I have to nudge the fan and it gets going fine. Temp comes down, goes back up, fan comes on fine. But I suspect the motor is on its way out.

I've tested the relay already. The fuse is fine.

All I want to do at this point is test the fan motor. I need to remove the connector from the coupling, but it's located under the air box and yikes I really don't want to mess with that (pic attached).

Any suggestions? Should I just cut the fan motor wire, test the motor, and reconnect the wires?

NOTE: regarding the attached image... it may or may not be the right connector, but if it's not that one, it's one underneath it that I can't get a photo of.

 

[gv550]

If the fan motor was getting 12v power, and prevented from turning, I think you may have burned the winding in one spot of the armature. A motor will often stop in the same place and your nudge just moves it to a spot where the armature is good. Once started it will motor past the burned spot and keep going, although at reduced power.

 

[RCinNC]

Removing the airbox isn't difficult, though it may look like it. It's only held on by a couple bolts, and there are (if I remember correctly) one electrical connection to disconnect on the right hand side of the airbox, and the crankcase breather tube that's attached to the bottom of the airbox with a hose clamp. That's the only thing that can be considered a little tough to reattach, but by no means insurmountable. You also have to loosen the clamps on the throttle body intake so you can pull the airbox out. Make sure you cover the throttle body openings once they're exposed. That's pretty much it. I'd rather do all that and find the right connector than to start cutting into wires and then have to splice them. If you're eventually going to change your own spark plugs, you'll have to know how to take the airbox out anyway.

 

[JoelG]

Removing the airbox isn't difficult, though it may look like it. It's only held on by a couple bolts, and there are (if I remember correctly) one electrical connection to disconnect on the right hand side of the airbox, and the crankcase breather tube that's attached to the bottom of the airbox with a hose clamp. That's the only thing that can be considered a little tough to reattach, but by no means insurmountable. You also have to loosen the clamps on the throttle body intake so you can pull the airbox out. Make sure you cover the throttle body openings once they're exposed. That's pretty much it. I'd rather do all that and find the right connector than to start cutting into wires and then have to splice them. If you're eventually going to change your own spark plugs, you'll have to know how to take the airbox out anyway.

Ok, perfect. I'll give that a shot. Thanks!

 

[RCinNC]

There may also be a small vacuum tube on the left side of the airbox; I can't remember for sure, and I can't confirm it without lifting the fuel tank. If you want, I can check the service manual before you tackle the job and confirm the procedure. Believe me though, if you're confident enough to cut into wiring and make electrical tests, you're definitely up to the airbox removal task.

 

[JoelG]

There may also be a small vacuum tube on the left side of the airbox; I can't remember for sure, and I can't confirm it without lifting the fuel tank. If you want, I can check the service manual before you tackle the job and confirm the procedure. Believe me though, if you're confident enough to cut into wiring and make electrical tests, you're definitely up to the airbox removal task.

I'll have a look. I've already got the fuel tank up, so may as well go the next step. I have the manual as well, just probably searched the wrong text to figure out how to remove it. Obviously, removing the air filter is a piece of cake... but just didn't dig deep enough to find the box removal instructions.

 

[JoelG]

If the fan motor was getting 12v power, and prevented from turning, I think you may have burned the winding in one spot of the armature. A motor will often stop in the same place and your nudge just moves it to a spot where the armature is good. Once started it will motor past the burned spot and keep going, although at reduced power.

Yes, this is my assumption. Just wanted to go through all the testing steps for practice. I'm certainly betting on needing a new motor.

 

[WJBertrand]

I'll have a look. I've already got the fuel tank up, so may as well go the next step. I have the manual as well, just probably searched the wrong text to figure out how to remove it. Obviously, removing the air filter is a piece of cake... but just didn't dig deep enough to find the box removal instructions.

You can remove the whole air box as a unit without opening it if you don't need to change the filter.

 

[JoelG]

You can remove the whole air box as a unit without opening it if you don't need to change the filter.

For sure. That's what I'm doing

 

[JoelG]

Ok, I got the entire air box out and it was easy. I think I just needed some assurance that it wasn't a big deal.

Managed to get the rad fan connector out and tested the motor by connecting to the battery directly. Same behaviour as when on the bike... won't start up unless I spin it to get it going. Sounds like I need to sort out getting a new motor or fan assembly.