Here is what my bike is doing - currently with a Power commander and V&H pipes. I was going down the highway at 70MPH and BAM - the speedometer goes to zero, and the engine light comes on. Then one second later everything returns, but I pull over and the bike dies. I restart and it's fine. Then next day I get three blocks from home and again, same behaviour. This time when I restart, nothing - no power when I turn the switch. I let it sit for about 3 minutes, then it starts back up. So I trailered it to the dealer - they say more than likely the Power commander is going out. I also had a low battery. They recommend yanking the PC and putting in a SERT.... to the tune of $800 installed. He did say however that they charged my battery and cruised it around for 10 miles or so without incident.

Am I getting the straight story here? Would my low battery have caused behaviour like this? I don't want to drop $800 and find out it's not the problem after all... Any input would be appreciated!!!

 

A bad battery will cause many strange things to happen. A friend of mine was having things like you said happening and I put my battery in his bike and it ran like new. Changed his for a new one and has had no trouble since. BTW his bike was stock.

Ride Safe,

Mike

 

aww man i had the same stuff happin!!! be cruzin and then i look down and 0 mph and yup once you stop dead. hit the starter and back in bizz. i've never had it not start tho. i figured my speed sensor was goiong but it hasnt done it for a few months now and was doin it like once a day cuz i ride to work all week. not sure what was causing it but i know when ever it happens i just turn the key off for a few and then restart and it comes back, sumtimes for just a second and goes out again. i have perfected this while flyin 80 on the freeway kinda scary to be rollin that fast and shut off hold the clutch in and wait a few seconds and then restart and let the clutch out and continue on like nothin happend. it mess the efi and computer stuff man its crazy the turn sigs wont self terminate cuz there tied to the speed sensor and maybe the throttle position sensor. very strange prob somewhat glad to hear someone else has it happining even tho its a bad thing. seems very spuratic on mine and will do it for a day a few times and then not for a few months and i cant remeber how long ago it did it last......at least 2 months now.

 

Bullpucky!

Tell them that if they >guarantee< that the PC is the problem and it turns out that it isn't, you expect them to >give< you the SERT and see what they say.

A low battery is a sign of any number of possible problems. but you first need to confirm that it is, in fact, low. You can go to any Advance Auto or Autozone store and they can test the battery for you if you don't have the right meter.

It also helps if you let us know what you are riding, how many miles, etc.

It is highly possible that all you have is a corroded or loose lead.

C#

 

I have to say, no, it is not your battery. If the battery is not powerful enough to drive the ignition and its control system it certainly won't be strong enough to operate the starter motor. Also, you said the first time it happend you were traveling at 70 mph. No matter what model you are riding that would have put you above 2000 RPM and at that engine speed your alternator should have been putting out power far in excess of your bike's needs - in short you were not running off your battery at 70, you were running on power generated by your alternator so battery condition (other than a dead short internal to the battery) would play no part in the bike dieing on that occasion. Also, if the battery had a dead short there would be no starting in the first place and certainly not after the bike died.

Sounds much more like a bad connection somewhere. Personally I always start looking on the ground side. If its not connections then if its a power delivery problem it has to be somewhere in the switching, and in fact that sounds a lot more like what your problem is to me. One way or another it also sounds like your dealer has a dead-eye set on your wallet and will feed you any kind of bunk to get at it.

 

Kong,
My dad has been a Harley mechanic for over 35 years. Based on his experience he says that a malfunctioning battery can cause all sorts of strange things to happen that may not seem logical to be the problem. On more than one occassion he has talked about something that has come into his shop looking like one thing only turning out to be a bad battery.

I think it is a good diagnosis for nevets to have his battery checked in addition to checking grounding as you stated to at least rule that out as a possibility.

 

i've check the battery and things seem in line. and whats happened to me is the speedo just will die not the bike but when you come to a stop shes runnin real low on the rpms and will sputter out and die. then you hit the starter button and it fires right up but will run a high idle for a minute before returning to normal. this may happen several times and i found that when the speed dies i can just turn the key off wait a few sec and then turn back on start and cont. thats what ive done either at stoplights or flyin down the road. every now and then if i cant shut down and restart (ie liek at night cuz the lights go off too!!!) the silly little speedo will kick back on by its self, however it will still sputter and die the first time you stop till you restart. its like sumthin cuzis an error and you have to turn the key off to reset it. very wierd and its sooo spuratic i really thought it was my speed sensor cuz oboviously the speedo kicks out. who knows theres demons on my ride but it hasnt happened for a good few months. thought i might just replace the speed sensor next time it happens....if ever who knows..

 

I know you don't want to hear this but it might be the ECU. I'd check its connections throughly. It delivers the info to the speedometer plus it sounds like when you turn it off & back on you're re-setting it.

 

How old is your battery & cables? What year bike?
Will the bike run OK if you disconnect the PC? How old is the PC? Are you running a hi flow air cleaner?
Lots of missing pieces to the story.

 

read my sign off.....i got just a S&S ac with a K&N in it as well as the S&S slip-on mufflers. thats it other than sum pretty stuff. lookin to get a kuryiakin wild things adjustable fuel module soon cuz she seems a little lean. its a 05 dyna super glide custom with 31,000 miles on and growin a 100 miles a day four days a week. battery and cables are stock got the bike brand new from the deal end of june 05. and i assume the "PC" yer talkin is a Power commandor??? havent done that as said above lookin in to the wold things by kuryiakin. its always seem to run fine just noticed the plugs gettin more white than tan and with the az summer heat right around the corner i want to richen the hoochie up. hope you have more of the puzzle now..