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Discussion Starter #1
After you shut the ignition off my fan still runs since it has been hot outside. This is probably due to the time it takes me to park the motorcycle into the garage after riding. My question is should you leave the key in the ignition in the first postion until the fan completes the cycle or just remove it and have the fan cut off early. Does it make any difference for the longevity of the motor?
 

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85 VN 700
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The fan will keep running with the key out if it needs to. At least mine does - and others have mentioned the same. It'll shut off when it needs to.
 

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Fan runs independant of the key, if thermal switch says turn on, the fan is on.

One reason why you disconnect the battery before working on it.

Jon
 

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Discussion Starter #4
I am not doubting your folks word but maybe my bike needs to be looked at. When I shut the bike off but the ignition key is still in the first postion(lights all work) the fan stays on. If I turn the the key off the fan stops running. This has been done several times over so I don't think it is a coincidence. The bike is a 06 but maybe I need to let the shop look at it. Thanks for the replies.
 

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Are you using the key to shut off the bike, or the kill switch on the right controls? If using the kill switch, that's why your lights stay on, you haven't turned off the ignition yet. If you are using the ignition to turn off the engine but the lights stay on, either you're turning the key too far to the left, Park position maybe, or something is just wrong with the ignition switch.
 

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Discussion Starter #6
My lights are on appropriately, I was just stating that so everyone would know which postion the key was in (motorcycle not running and fan and light are running). Sorry for the confusion. I really don't mind waiting for the fan to stop running before turning the key all the way off but was concerned about the battery. I purchaced a maintenance free battery along with several other add on goodies but between the kids and work have not been able to chisel enough time to put them on. I really appreciate the help from everyone on this board. I have been on other nonrelated boards and the people on those are not nearly as helpful as this group.
 

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You don't need to keep your lights on for the fan to run, unless something is wrong. I guess I'm still confused. You're turning off the key and the fan quits? If you turn the key back on immediately does the fan come back on?

Are you using the kill switch to kill the engine? Or the key?
 

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Discussion Starter #8
I am using the kill switch to stop the engine. I then turn the key from run to the left which leaves the lights(neutral finder ect on) and the fan continues to run. When I then take the key and turn to the left into the position that it can be removed the fan stops running immeadiately(as if power to the fan has been cut). I have not, and it is a good point, tried to turn the key back on to see if the fan then starts running again. I rode the bike to work today and I will try this when I get home. Thanks.
 

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Even if the fan cuts out, it is only drawing air through the radiator. If the engine is not running, there is no water circulation through the engine so the fan shutting off won't hurt the engine. The radiator will take longer to cool though.
 

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Benjammin'
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A couple of comments;
1) If the fan runs with the engine off, it will still continue to move air across the engine, slightly helping it to cool. Corretc?
2) I have heard that turning the engine off with the key could cause the contacts inside the key switch to arc and possibly prematurely fail. Not real sure about this one, but as long as I have a run switch, I prefer to use it instead of the key.

Thoughts?
 

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the engine is of course hottest right after you turn it off- no air from moving, and the water stops circulating-- so anything you can do to keep it cooler-- like the fan air is a good thing-- if you are gonna overheat-- its that moment when you shut everything down!
 

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and the Adventure Cycle
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A couple of comments;
1) If the fan runs with the engine off, it will still continue to move air across the engine, slightly helping it to cool. Corretc?
2) I have heard that turning the engine off with the key could cause the contacts inside the key switch to arc and possibly prematurely fail. Not real sure about this one, but as long as I have a run switch, I prefer to use it instead of the key.

Thoughts?

I suppose there would be some air from the fan hitting the engine, but I wouldn't think it's all that much. After all, any air that would make it to the engine would be cooling, at the very most, only 1/4 of the enging surface, and that's only taking into account the jugs of the engine, and not the lower portion.

You do have a good point about the ignition switch verses the kill switch though. I never really though about it like that, but I do usually use the kill switch first, then the key (atleast when my bike was running!)
 

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I wouldn't dissagree with the kill switch vs the ignition switch, but anything that draws much current would be going through a relay so the ignition switch would be feeding those relays with a signal current, nothing more, so although it probably would extend the life of the ignition switch to only use the kill switch, it doesn't seem that it would make a huge difference. Just my uneducated guess! ;)
 

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it cools more than 1/4th the engine. the point is that heat is radiating out of the engine into the air, and the fan blows the hot air away from the bike and brings in new cool air to replace it-- in a continuous fashion. it does not need to hit the surface of the engine directly to help circulate the air around the engine-

displacement of thermal energy is related to surface area and temperature drop between the meeting surfaces-> so you want the coolest air over the most surface area to get the best results.

no fan means the air just sits there cooking your bike in its own heat as it gets less and less efficient at shedding the heat--

so yes, let the fan do its work!
 

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Now what
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I am not doubting your folks word but maybe my bike needs to be looked at. When I shut the bike off but the ignition key is still in the first postion(lights all work) the fan stays on. If I turn the the key off the fan stops running. This has been done several times over so I don't think it is a coincidence. The bike is a 06 but maybe I need to let the shop look at it. Thanks for the replies.
Looking at the schematic for the cooling fan, the ignition switch appears to be completely out of the fan circuit. White wire with the red stripe goes to the main fuse in the junction box. Fan relay gets its power from that fuse. When the fan switch closes, relay turns the fan on. Shouldn't matter what position the ignition key's at-or even if it's in the switch. Have you looked at the junction box to check for damage from battery acid? It seems like a long shot that acid could cause such specific behavior, but I don't know what else would cause it, unless somebody added some electrical accessories like lights. I don't know how, but it sounds like the fan's getting its power from a switched circuit now instead of straight from the battery.
 

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Discussion Starter #16
Mr Ironman,

You may be closer than you think. The other day I pulled into the garage and turned the key to off and removed it after killing the bike with the red kill switch and the fan continued to run for a short while and then turned off. The part about the battery acid is a little scary. I looked under the bike the other day and below the battery box appears to be dried battery acid on fins. I am on call today and won't be home until the a.m. but plan to remove the battery and replace with the MFB that I purchased a while back. My biggest worry is that while trailering the bike back from Ohio that the bouncing trailer caused a acid spill. I am not sure if it is acid or just road grime but I plan to wash out and neutralize with bicarb first thing in the a.m. that is if it ever gets here. 24 hour shifts suck.
 

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and the Adventure Cycle
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I looked under the bike the other day and below the battery box appears to be dried battery acid on fins.
The fins are from the regulator/rectifier. If you determin it is battery acid, it wouldn't hurt to check the plug on it and make sure it's not loaded with corrosion also.
 
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