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Discussion Starter #1 (Edited)
so this has happened to me to few times lately. Basically i go to start the bike after its been sitting for a couple of weeks and the battery is dead. I checked all the normal things, like did i not turn the key all the way off and left the lights on or anything like that. once i charge the battery and reinstall it everything starts right up. i always check to see if anything came on or if i heard a noise or anything when i first connect the battery, hoping to find what has been draining it, but no luck. finally this morning when i was reinstalling the battery i heard the fan kick on. it ran the whole time i was putting the seat back on. i wasnt in a hurry so it was a few minutes. i drove around the block and parked the bike again. the fan ran for a second and then cut off, like it should.

has anyone experienced this? is the fan even connected to this issue? what else could be draining the battery? it is a new battery bought this July and the bike is completely stock.

thanks for the help!
 

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1986 VN750
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Are you sure your bike is charging the battery when you're running it? Check voltage @ the battery with the bike running. You want to see near 14v @ 5000rpms.

Otherwise you could simply have a bad battery.

(didn't see the fan was on when cold? it's ok for it to come on after you turn the bike off when hot but shouldn't run when cold)
 

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finally this morning when i was reinstalling the battery i heard the fan kick on. it ran the whole time i was putting the seat back on. i wasnt in a hurry so it was a few minutes.
Probably a bad fan switch and the fan is kicking on when you're not around. It shouldn't have been running if the bike was cold.
 

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or a possible short in the wiring harness that leads to the switch. most common location is under the neck covers
True, the fan switch works by grounding, so if that single wire grounds anywhere, the fan should kick on.
 

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Discussion Starter #6
cool. thanks for the tips. i know what i am doing this weekend! i will keep you updated.
 

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Discussion Starter #7 (Edited)
well, im not sure if this is part of the problem, but when i started to track down the wires, i started at the fan and the fan switch on the radiator. as soon as i touched the connection between the hot wire and the fan switch it broke right off. it was rusted completely through. so even if that wasnt the problem, and there is still a ground some where the fan will not be draining the battery. on the down side, the fan will not turn on now. i looked up the part and it is $100.00+. :frown2:
 

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you can find used radiator assy on ebay for much less, and some even include the fan and shroud
Yes, I posted one yesterday, $36 for radiator, fan, switches and all. shipped. Posted in a thread about overheating. The person in that thread had a fan switch kicking on at the wrong time also.
 

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Discussion Starter #10
went to start the bike this morning and it was dead again. so either the fan is still draining the battery even though the fan switch is completely disconnected or something else is draining the battery. on an up note, i did find radiator on ebay for $20. so thanks for that info!
 

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FREEBIRDS MC CENTRAL NY
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How old is the battery and is it an agm?
 

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Discussion Starter #12
i bought the battery in june or july of this year. so its only 4 or 5 months old. and i dont know about agm or not. i needed a new battery and it was the only one the store had. so i bought it. i will take a look.
 

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FREEBIRDS MC CENTRAL NY
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If you had to fill it with acid it's not an agm.agm batteries are sealed.try disconnecting the battery next time it a its to see if it is the battery or not
 

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Discussion Starter #14
i dont think its the battery. before i started the post i did exactly what you suggested. i charged it. rode the bike around a bit, parked it and then disconnected the battery. the next day i reconnected the battery and the bike started right up.

i figured it was charging fine, but just to be sure i measured it. with the battery fully charged the meter read 13.5vdc. i hooked the battery up again, and strangely, the fan kicked on again, even though the fan switch is disconnected. i started the bike and at 2,000rpm it was reading 14.2vdc. getting the rpms up to 4,000, the voltage dropped to 13.5vdc. either way, its charging. i let the engine get pretty hot and touched the fan switch wire to the fan switch and the fan kicked on, but once i took the wire off the switch the fan continued to stay one for about 1 minute. then when i would touch the wire to the switch the fan would come on and as soon as i removed the wire it would turn off.
 
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