| Author | Message | ||
     Dr_greg |
So I'm finally gonna replace my ailing fan. But upon removal, it spins freely by hand (unlike my previous dead fan) and spins fine when connected to a battery (like the new one). However, I notice the fan is driven directly from the ECM, which can't be able to source much current. So probably the "old" fan is really bad, and only runs off the battery because it can draw as much current as it needs. So I'll install the new fan (had it for years) and I suspect I'll be good to go. FWIW, the "old" fan is the one from my original Uly, so it has approximately 70,000 "miles" on it. Not bad, I guess. Also, despite my "American Motorcycles" badge, the fan is made in Italy. Never noticed that before; pretty classy! --Doc | ||
| Natexlh1000 |
Does the "bad" fan turn equally well in all positions? When you have them both out, hook them up in series with each other and connect them to a battery. Then you will see which one draws more current! | ||
| Pso |
Did they upgrade the 06 fans that seemed to go bad frequently? | ||
| Froggy |
The 2010 fans are the exact same as the 2003. There hasn't been any changes as far as I can tell. Just a batch that was more failure prone on the 06's. | ||
| Ratbuell |
That's an interesting point about the ECM power...can anyone confirm it? Got me thinking about a relay system now...ECM triggers a relay, which turns on the fan. 'Course, it would eliminate the hi/lo speed function...and since I haven't had a single fan issue with my '06 yet I should just leave well enough alone  | ||
| Natexlh1000 |
The relay idea is probably a good one except that there are two fan speeds. the ECU probably varies the fan speed with MOSFETS and a pulse width modulation. Those fans take a good bunch of power, right? | ||
| Towpro |
But doesn't the ECM run the fan at 2 different speeds? When I first turn mine off hot, the fan is real loud, then it seems to go down to 1/2 volume (and I assume speed). | ||
| Dr_greg |
Yes. However, it does have more "cogging" than the new fan. Great idea! I'll do that and report back. Why didn't I think of that. Was gonna scrounge an ammeter, but... My confirmation was from the schematic: direct connection from pin 6 on one ECM connector directly to the fan. No power electronics in the circuit. Probably a MOSFET output circuit doing PWM (pulse-width modulation). Can probably source a few amps, but not much more w/o a heat sink (I would think...) The ECM controls the "duty cycle" of the PWM waveform to obtain the two speeds...pretty standard DC motor drive stuff. It can't be the temperature sensor itself, because I assume the resistance of the sensor tells the ECM which of the three waveforms to use on the fan (OFF, LO, HI). And the ECM surely can't be bad... Right?!?! BTW, my symptoms are: fan not running, or fan running very sluggishly and unevenly. I expected the fan to have noticeable friction (like my previous '06 fan which failed) but it seems very free. The greater cogging may be significant, however. I'll get it solved; this isn't rocket science. --Doc | ||
| Dio |
I'm no extreme electronics whiz, but can find my way around the basics with ease. Please enlighten me (and perhaps others) on the concept of hooking the 2 fans together in series to see which one draws more current. This is new to me. | ||
| Natexlh1000 |
If you hook up two things in series, they will have the same current as each other. If one fan is sick, it will turn slower. Think of this: Hook a headlight and a turn signal in series. One will be brighter, right? But the current through both is the same. | ||
| Dr_greg |
Fan update: I connected each fan to my old battery charger, which can source 1.2A max, and has a built-in ammeter (easier than driving both fans). The "new" fan draws slightly MORE current (about 800 mA) than the "bad" fan! Yikes! The "bad" fan makes a little more bearing noise, but---if anything---spins faster.  Sigh. I guess I'll install the "new" fan and hope for the best. If it still gives trouble I'll put a scope on the fan signal and temporarily replace the sensor input to the ECM with a voltage/resistance I can vary. Better not be the ECM; I have a spare but this one works better for low-speed fueling. And it better not be the temp sensor cuz it'll probably be back-ordered for a couple years, right? Hmm, maybe time to test-ride an F800GS. Dang it. I had just fallen in love the Uly again after my brief flirtation with the 1200GS. --Doc PS. Maybe I'll just ditch the fan, period.  Hey, I've got a backup engine. What, me worry? | ||
| Pso |
Have they fixed the bearing issue on the F800GS yet? | ||
| Dr_greg |
Mistake on the fan current: "new" fan draws about 3.5A. Was reading the wrong scale. Dunno about the 800GS; not concerned about that now. First things first. Gonna spend the rest of the day putting this bike back together. I disassembled the entire rear subframe, etc. since I got lots of mud in it from my last ride. Hopefully a fan report before the COB today. --Doc | ||
| Dr_greg |
Actually, I just noticed the "flowchart" on p. 4-83 of the FSM, "Cooling Fan Does Not Run." That isn't quite my problem, but I think I'll follow it after I get the bike partially assembled. Woulda done as I tore it down if I'd noticed...oh, well. When in doubt, read the directions. BTW, one of the flowchart paths terminate in block "REPLACE ECM." Hope I don't end up there. --Doc | ||
| Dr_greg |
Hmm, upon further inspection of the flowchart, all endpoints are "REPLACE ECM", "REPLACE FAN", or "FIX OPEN CIRCUIT." Since my fan runs intermittently, probably not helpful. --Doc | ||
| Garrcano |
Maybe it helps: - Check the blue 10A fuse "Cooling Fan" - Check the red wire on pin 35 on fuse block (power inlet to the fuse) - Check the yellow/brown wire on pin 41 on fuse block (power outlet to the fan). It goes directly to pin 1 of the fan (on connector 97 it converts to yellow). - The fan gets ground from the ECM, so check the ground points in battery area and pin 6 (black/orange) on grey connector of ECM - With "check" I mean moving, pulling and visual for corrosion/oxidation on all connections | ||
| Dr_greg |
Yes, all good suggestions. I'm using contact cleaner and checking/cleaning all connections that relate to the fan. Thanks. --Doc | ||
| Tootal |
I believe the grease used in some of the 06 fans was breaking down causing bearing failure. They changed the grease in later models and no problem. If they have been using the same fan since 03 then the vendor went with the cheap grease in 06 hoping nobody would notice his increase in profits!! | ||
| Dr_greg |
Got the Uly assembled enough to start it, so I ran it outside for 10 minutes (33F temp), and...THE FAN WORKS PERFECTLY! I'm still not convinced the "old" fan was bad, so I'm keeping it. I cleaned several connectors; that could have been it. Anyway, I'm happy. Now to assemble the rest of the rear part of the bike...surprisingly tricky; the order is important. I have this week off, so hopefully some riding, but the weather (even in sunny NM) is bad. --Doc | ||
| Froggy |
You could of used ECMspy and ran a diagnostic on the fan | ||
| Natexlh1000 |
There is a diagnostic for the fan in the ECM? I thought the only way to test it was to supply 12V and see what happens. | ||
| Tootal |
ECMSPY on the diagnostic page will test O2 sensors, fan, fuel pump, etc. You might have to be in professional mode to do it but it's real easy, even for a computer illiterate like me!! | ||
| Natexlh1000 |
Does it test the fan by just turning it on or does it do something fancy? | ||
| Tootal |
It runs for a few seconds and then gives you a good or bad reading. Don't know what it looks at though. | ||
| Natexlh1000 |
Do the fans have more than a pair of wires? Most computer fans have a tach output. |
