fan control

[BuddyB]

Hello, I know this has been talked about a few times and I'll take some grief bringing it back up but... I'm curious. My 07 xb 12 lightning's fan comes on when I ride 1) hard 2) long on warm days and 3) pretty much every time I shut the bike off after riding 20 minutes or more.

I assume it is trying to cool the back cylinder and keep it from cooking the oil. Correct?

I have recently had a chance to ride a 2009 xb 12 lightning and the fan comes on all the time while riding. OK. The info on the forum threads seems to indicate the later XB12's fan was programed to come on at either RPM or temp. Correct?

But it does shut off when I get to a stop.

So, can I assume that the fan coming on while the bike is in motion is cooling it enough that at a long stoplight or in heavy traffic the fan shutting down simply makes it basically the same temperature as the front cylinder which is not getting any airflow while the bike is stationary?

I'd like a opinion or two.

 

[BuddyB]

Alright got it figured out.

 

[c3powil]

Seems like you already came to a conclusion, but my guess is yes. The fan cools the rear head during running and doesn't need to cool it when off. I really wish my '05 xb9 had that feature.

 

[motoguy]

Seems like you already came to a conclusion, but my guess is yes. The fan cools the rear head during running and doesn't need to cool it when off. I really wish my '05 xb9 had that feature.

My Buelltooth arrived a few days ago. I plan on getting the proper maps for my drummer and the updated fan programming.

 

[motoguy]

Are there any suggestions on fan settings for optimum rear cylinder cooling? More worried about longevity than anything else. I have zero concern about fan noise.

 

[BuddyB]

The general thinking as I see it is that the fan will come on to cease damage to the rear cylinder and possibly the oil. So from what I gather, the fan is programed to go on at a particular temp in the earlier models. Thus the fan will run until the temp reaches a satisfactory temperature and the fan will run for however long it takes to keep the rear head at optimal temperature. My 07 will come on when it gets hot and will continue to run when I shut the bike down until the temp is below the threshold of the rear cylinder.

The 09 will run the fan any time it gets to it's threshold, and that apparently can be RPM or temp controlled. But the 09 will not run the fan after I turn the bike off, so I assume the head temp is at a suitable temperature to not warrant the fan to come on. And the 09 will turn the fan off when the bike comes to a stop light.

Though I still tend to wonder if I was riding real hard and was coming to a stop light, if the fan would eventually come on. The 09 I'm riding does have a right side scoop, and it seems to not be too hot.

Enough

 

[Cooter]

Both DDFI-2 and DDFI-3 ECMs have the same fan controls:

Ignition ON (fan on and off temps)

Ignition OFF (Fan on and off temps) Usually set slightly lower and that is why the fan sometimes kicks on when you park.

'Speed based fan control' on or off. The fan will be triggered to run above +/-25mph. IMO bad. Hard on the stator, voltage regulator, wears out the fan, coats it with more oil from a weepy rocker box, and pointless as theres plenty more air at 25mph than that little fan could ever provide.