Fan stopped working

[Epping]

After a trip to Philip Island to watch the Island Classic races on the week end, I joined the long slow crawl off the Island and for the next hour in 35+ deg c. The temperature light came on & I noticed a trail of fluid out the back of the bike. The fan was not running. The fuse had blown. The fan had probably had a hard time the previous day. 16 hours on some pretty rough fire trails and transmission line tracks at slow speed also above 35deg. Anyway, replaced the fuse & still no fan and a scraping noise when spinning the blades by hand. Sounds terminal.

 

[Tremor38]

After a trip to Philip Island to watch the Island Classic races on the week end, I joined the long slow crawl off the Island and for the next hour in 35+ deg c. The temperature light came on & I noticed a trail of fluid out the back of the bike. The fan was not running. The fuse had blown. The fan had probably had a hard time the previous day. 16 hours on some pretty rough fire trails and transmission line tracks at slow speed also above 35deg. Anyway, replaced the fuse & still no fan and a scraping noise when spinning the blades by hand. Sounds terminal.

Sounds bent. Did you dump the bike on that side at any time?

 

[Buelligan]

I had this happen on my Buell 1125. Noticed the temp creeping up, and pulled over to check it out. Blown fuse. Replaced the fuse and it blew right away. Started checking my fans, and found a small piece of a twig in one of them. (two side radiators, with one fan each) Apparently it had been there awhile, and had burned up that fan. I was able to disconnect that fan, replace the fuse, and continue on with my trip.
The fan was replaced upon my return, under warranty.
Unfortunately, you don't have that option, when you only have one radiator, and one fan. You can disconnect the fan, and use an OHM meter to check for resistance. There should be around 5 ohms resistance if the fan motor is good. If it shows 0, it's shorted, and if it shows open, it's burnt up. either way, if it's still under warranty, by all means bring it in...

 

[Koinz]

I had this happen on my Buell 1125. Noticed the temp creeping up, and pulled over to check it out. Blown fuse. Replaced the fuse and it blew right away. Started checking my fans, and found a small piece of a twig in one of them. (two side radiators, with one fan each) Apparently it had been there awhile, and had burned up that fan. I was able to disconnect that fan, replace the fuse, and continue on with my trip.
The fan was replaced upon my return, under warranty.
Unfortunately, you don't have that option, when you only have one radiator, and one fan. You can disconnect the fan, and use an OHM meter to check for resistance. There should be around 5 ohms resistance if the fan motor is good. If it shows 0, it's shorted, and if it shows open, it's burnt up. either way, if it's still under warranty, by all means bring it in...

I guess for some extra cooling capacity, we could mount an extra radiator to the front of the bike in series with the side mounted radiator for those really hot backroad trips. ::001::

 

[Epping]

You can disconnect the fan, and use an OHM meter to check for resistance. There should be around 5 ohms resistance if the fan motor is good. If it shows 0, it's shorted, and if it shows open, it's burnt up. either way, if it's still under warranty, by all means bring it in...

I'll give this a try. Thanks. I would have thought if the fan was jammed, the fuse blowing would protect the fan motor. No point in a fuse otherwise.

 

[dcstrom]

I'll give this a try. Thanks. I would have thought if the fan was jammed, the fuse blowing would protect the fan motor. No point in a fuse otherwise.

That wouldn't be the first time I've heard that - the Sth Efricans burned out a fan motor when they crashed the bike on the "Doodsakker" ride. The fuse, or something, should prevent this from happening.

 

[AVGeek]

When I dumped mine on the left side, I had the exact same thing happen. The fan motor appears to be pretty damn fragile, and will burn out before the fuse can blow. The mounting brackets for the fan are also very easy to bend; there was no damage to my radiator at all.

 

[dcstrom]

When I dumped mine on the left side, I had the exact same thing happen. The fan motor appears to be pretty damn fragile, and will burn out before the fuse can blow. The mounting brackets for the fan are also very easy to bend; there was no damage to my radiator at all.

Where are the electrical experts? Would it be a good idea to use a lower rated fuse for the fan?

 

[Bundu]

I would think one would have to make sure fan has it's own fuse, stall the fan and measure the current and fit a slow blow fuse of slightly lower capacity to stalling current and then check to make sure startup current doesn't blow fuse - my guess....

 

[GrahamD]

Epping, I happen to be in possession of an S10 fan. (amongst other parts)

I'll see If I can get an idea on some Positech (tm) device sizes for you.

The fuse in the S10 is over rated for the "Siren" I think.

I'll do some measuring as soon as I get a free moment. Or you can pop in for a Shed day/hour.

Cheers
Graham

 

[dcstrom]

Epping, I happen to be in possession of an S10 fan. (amongst other parts)

WHAAAAATTTT? Do NOT tell me you have enough "other parts" to make a complete motorcycle? If so this is
BIG NEWS

Or maybe you are just slowly collecting parts as the budget allows, and putting them together some time down the track?? I guess that's a way of building a Super Tenere in parallel with renovating the house.... By the time the house is finished, the bike will be ready.

We need pics!

 

[GrahamD]

WHAAAAATTTT? Do NOT tell me you have enough "other parts" to make a complete motorcycle? If so this is
BIG NEWS

Or maybe you are just slowly collecting parts as the budget allows, and putting them together some time down the track?? I guess that's a way of building a Super Tenere in parallel with renovating the house.... By the time the house is finished, the bike will be ready.

We need pics!

You must be a happily Married (or equiv) man DC.

I have been dropping subtle hints all over the place, and it took An (Ex) Aussie to get it. ::008::

Yes, I have enough "parts" to make a whole S10. In fact YAMAHA even assembled them for me. ;D

But the News is not really pink. It's more blue.

 

[Epping]

Well, good news on the Fan front. Replaced under warranty ::012:: Very pleased with Customer Service from Red Baron at Liverpool where I purchased the bike. Great Guys. ::008:: I had found fan was open circuit. Strange as the fuse had blown so expected short circuit. Anyway, they fitted new fan while I waited. Bought LED indicators while there. I find the fronts too bright and distracting at night. Not yet installed. This bike just gets better & better. ::022::

 

[GrahamD]

Good to hear ::008::

 

[Buelligan]

"I had found fan was open circuit. Strange as the fuse had blown so expected short circuit."

Actually, this makes sense, because before the windings of the fan motor burn out, and create an open circuit, they are pulling maximum amps trying to spin the stuck fan.
so the fuse probably blew at the same instant the motor windings burned.
Glad to hear it was repaired under warranty!

 

[dcstrom]

So, what's the expert conclusion on this? Does it make sense to change to a fuse with a lower rating? Seems to me that the fuse is not doing its job of it doesn't blow BEFORE the fan motor burns out?

This is not the first time I've heard of this problem...

 

[markjenn]

We may be between a rock and a hard place on this. Startup current for an electric motor is several times steady-state current, so a fuse big enough to handle startup demands may be too big to blow when the fan is drawing enough extra current to overheat due to an obstruction.

You could certainly start dropping the fuse amperage to try and find the lowest that doesn't routinely blow in normal operation. But that would be a fair amount of trail and error and just might turn out to be about what Yamaha has in there. I doubt Yamaha spec'ed a way-too-big fuse just for the heck of it.

One approach is to leave it stock, but do a fan check anytime you suspect an obstruction (e.g., after a left-side tipover). Any obstruction enough to overheat the fan is probably going to be audible standing beside the bike if you're listening for it.

- Mark

 

[GrahamD]

So, what's the expert conclusion on this? Does it make sense to change to a fuse with a lower rating? Seems to me that the fuse is not doing its job of it doesn't blow BEFORE the fan motor burns out?

This is not the first time I've heard of this problem...

The old tech solution is to find a SLO-BLO fuse with the right curve to survive the initial startup current and blow in the case of a stall BEFORE the motor.

The new tech solution is to fit a PTC thermister (EG Positech (tm)) with the appropriate hysteresis that will go high resistance at the correct current. I'm trying to get to that solution.

Having said that, the fan just may not be rated for 100% duty cycle and may just poo itself if asked to run continuously in high temps for too long.

1 years testing in Northern Africa suggests that this has been looked at and tested, however that doesn't mean production batches have high tolerances.
So far 1 seems to have had a failure. Could have just thrown a winding due to a bad solder joint or something.

Cheers
Graham

 

[528Hz]

how about some fine mesh behind the cover to keep really small stuff from getting in there, like window screen type mesh.