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Discussion Starter #1
I have a 2003 LT. I posted before that I am have a battery draining to dead. It used to take several days then two days and then the same day I charged it. I have noticed that when I connect the bike leads with the ignition off I get an arc connecting the battery lead.
Posted this before and it was suggested to connect a meter in line to the negative lead and pull fuses until the drain stops. Well I was ready to do that but I decided to cheat. I pulled all the fuses from every bank. Then with the ignition off I struck the negative lead to the battery terminal. It still arcs! A little less then with the fuses connected but still there.
I have had the battery on a battery tender for several weeks after it started dying the same day I rode it. Just for grins I had the dealer check it three months ago on the million dollar BMW battery tester and it tested fine. Today I went to the auto store and had it tested the battery is not putting out 11 amp. The bike will not even click when you try to start it and the ABS blinks to show low voltage.
So which is the chicken which it the egg. It I pull all the fuses with the ignition and radio off and strike the negative lead on the battery I should not get nothing right! The only other thing I can think is that there is a short in the wiring harness somewhere that bypasses being fused? Or could the battery be shorted inside?
I do remember at one point in July I took a jump from a running car when the problem first appeared. Someone told me that was REALLY bad for the bike since it runs on 20 or so amps and car runs at 200. But the bike was fine for 2 months after that after. I would think if that was the real problem I would have had immediate issues with the bike the very next day!
In looking around I see some things about the starter and alternator but how could they be the problem with the ignition off.
I did find out why the bike is running warm the last month I road it. BMW fuses the radiator blowers separately. The left blower fuse was blown.
The only accessory I have on the bike is fog lamps that I viper clamped off the head light leads. I even cut those wires and I still have the problem.
I talked to BMW about running it on the bike computer. They said it would not run down electrical problems I was on my own! :dance:
 

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Similar experience a couple months ago. Finally stopped for some corn on the way home and wouldn't turn over. Fortunately the farmer had a nice slope down to the barn where the battery charger was. Popped the clutch while rolling toward barn and varoom. Made it the last 2 miles. Bought a new battery and no problems.
 

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You never told us how old the battery is???
If it's more than 2-3 years old, why are you "beating yourself up"
with your spark test theory?
If your battery has gone dead more than once or twice that alone could cause internal battery damage.

Instead of pulling your hair out, pull your wallet out and get a new battery.
 

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wkane4 said:
I have a 2003 LT. I posted before that I am have a battery draining to dead. It used to take several days then two days and then the same day I charged it. I have noticed that when I connect the bike leads with the ignition off I get an arc connecting the battery lead.
Posted this before and it was suggested to connect a meter in line to the negative lead and pull fuses until the drain stops. Well I was ready to do that but I decided to cheat. I pulled all the fuses from every bank. Then with the ignition off I struck the negative lead to the battery terminal. It still arcs! A little less then with the fuses connected but still there.
I have had the battery on a battery tender for several weeks after it started dying the same day I rode it. Just for grins I had the dealer check it three months ago on the million dollar BMW battery tester and it tested fine. Today I went to the auto store and had it tested the battery is not putting out 11 amp. The bike will not even click when you try to start it and the ABS blinks to show low voltage.
So which is the chicken which it the egg. It I pull all the fuses with the ignition and radio off and strike the negative lead on the battery I should not get nothing right! The only other thing I can think is that there is a short in the wiring harness somewhere that bypasses being fused? Or could the battery be shorted inside?
I do remember at one point in July I took a jump from a running car when the problem first appeared. Someone told me that was REALLY bad for the bike since it runs on 20 or so amps and car runs at 200. But the bike was fine for 2 months after that after. I would think if that was the real problem I would have had immediate issues with the bike the very next day!
In looking around I see some things about the starter and alternator but how could they be the problem with the ignition off.
I did find out why the bike is running warm the last month I road it. BMW fuses the radiator blowers separately. The left blower fuse was blown.
The only accessory I have on the bike is fog lamps that I viper clamped off the head light leads. I even cut those wires and I still have the problem.
I talked to BMW about running it on the bike computer. They said it would not run down electrical problems I was on my own! :dance:

The LT has circuits that are always hot & not fused. They are very low current draw but can still cause the arch that you describe. I would definitely change out the battery and go from there.
 

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hp1bmw said:
The LT has circuits that are always hot & not fused. They are very low current draw but can still cause the arch that you describe. I would definitely change out the battery and go from there.
+ 1 I have a quick disconnect on the negative side of the batt. and no matter which fuses I pull it still sparks when I connect it back. Like Hans said try a new batt.
 

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One I can think of is the radio. It has juice to it direct from the battery and it is fused at 10 amps but the fuse is on the back of the radio. Seriously the ONLY way to find a bad drain current is with a meter. The arc when you connect tells you nothing.

I have a friend who spent a few hundred at the dealer trying to track down his current drain. No joy. I spent 15 minutes with a meter measuring the key off current drain while I started disconnecting a rats nest of wires and found an antenna amp that was drawing 150 milliamps. Once I disconnected that it settled down to just a few (5-7) milliamps, which is normal.

Just change the battery but get a meter and track down and disconnect anything in excess of 10 miliamps.
 

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As others have said, this is a job for someone who knows how to use a multimeter, and trace the problem to the source. Will likely take some time, and pulling of all the Tupperware and unplugging a lot of connectors. Having the electrical diagrams for the bike will be just about necessary.

Another thing: Jump starting the bike from a running car is NOT wrong. In fact you WANT the car to be running to supply the full 13.7 volts to overcome resistance in the jumper cables, and supply at least 12 volts to start the bike. I did it several times to my and other's motorcycles. The person who talked about amps knew nothing about electrical circuits at all, period. You could jump the bike from a semi or bus if they are running on a 12 volt battery system. Only the VOLTAGE has to match. The source can be capable of supplying thousands of amps, the device being driven by that voltage determines the amps drawn. Look at it this way: The bulbs in the instrument panel use a fraction of an amp, although the battery is capable of supplying a couple hundred amps for a short time.

The electrical supply into your home is probably protected by a 200 amp breaker, the supply is capable of supplying a thousand or so until the wires overheat. Yet, you can plug in a 4 watt night light, it will not burn out from over current, when what the light it is plugged into is a 15 or 20 amp protected circuit. Same with jumping your LT from a running car. Both systems run at around 13.7 volts engines running, so there is no way any other 13.7 volt supply can harm the bike (unless you hook the jumper cables up backwards!).
 

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Discussion Starter #8
Thank you for all your follow up comments. The battery is a BMW factory battery and it is 9 months old.
As far as the radio fuse. I checked the manual again is it is fuse 8 listed in the travel book provided for the bike.
I have been through every visible harness directly under the seat. I did find one location where the ground wire had either worn or burn off a 1/4" of the outer casing. I could not tell which. I taped it off to make sure it was not contacting the frame.
I remember someone in some posting mentioning an electrical problem being solved because the ground strap was not connected on the lower part of the bike near the foot peg. got up under the bike I didn't see anything.
As far as the spark with the battery all I can base that on is my experience with cars. I never had that happen when I have cleaned terminals on a car battery and replace them. That is all I have to relate it too.
Thank you all in advance for any advice or interest that you are showing a fellow rider!
 

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Discussion Starter #9
Before anyone notices... I forgot to mention the battery has a one year warranty and yeah I will be returning it to the dealer.
Thanks for the last post about jumping from a car that really help set me straight on the issue!
You guys are the best!
 

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Discussion Starter #10
I have what I think is the 170 page manual for the bike that shows everything from unpacking to filling up the tires. It does not include anything about wiring and harnesses. Were do you get that from?
 

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The Clymers Manual is the only one that I know of with all the wiring diagrams for all the KLT series bikes. I got the internet download manual that was junk. Then when I had to get serious about some of the innards and electrical sections of the bike I had to spring for the manual. I think I got it from Amazon.com somewhere around $40 bucks. My LT is a '99 model, first year, but with many upgrades so it thinks it about a '99.9 model.

Be careful with batteries. No rings, watches or bracelets on the hands or fingers when working around them. Just my .02 cents worth.
 

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I had similar symptoms to yours and it was a defective BMW battery, replaced under warranty. Find out for sure whether your battery is good or bad

On any bike that was having battery problems I would want to know what the dc charging voltage is. If the alternator is not up to snuff it could be allowing the battery to remain in a constant state of slight discharge and over time this will damage the battery. I'm not sure how sensitive the charge light is on the bike for detecting a weak alternator, make sure your light is working when you turn the key on.

After a full charge and then setting for a while the battery should read around 12.5 volts, might want to turn the key on and off for a few seconds to confirm it is holding in that voltage range, low level load test. When you start the bike it should be somewhere between 13-14 volts from idle through revs, mine is quite stable at all rpms at 13.9 - 14. Record the number so over time you can see if anything is changing.

Get a multimeter, even if its a cheap one to check the basics, DC and resistance (ohms). I saw them at harbor freight last week for $4.99 and free with a $10 purchase.
 

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You really need to use a meter to find or confirm that you even have excessive amp draw, spark test will not do it. There's no sense in pulling fuses or connectors if you don't know the amp draw is excessive. It can be a fault in the battery but to keep from guessing put a meter on it, I don't think a $5.00 HR meter will be very accurate in the milliamp range but it's got to be better then a spark test.

If you do find that the amp draw is excessive and pulling fuses doesn't drop it a print will be your friend. you need a schematic with the number standard on the wires. anything with a 30, other then a relay, indicates 12V+ all the time. start there. A15 indicates switched 12V+, go there next. A hot short to ground will be easy to find after the smoke settles so I wouldn't focus on a short to ground as the draw.BUT, before even getting into this and pulling what's left of your hair out, put a meter on it. If the amp draw is in spec. get a battery.
 

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This is very interesting...... Does this apply to firing up your bike from a car battery (not connected to the car) I.e. the car is not running??

It is 12v of course and capable of delivering mega humph because it normally fires up a 2500 cc diesel. Does the bike simply take what it needs rather than having all that humph!?

Thank you for your help in this matter..... And I hope OP gets his sorted.

Cheers

Stuart



dshealey said:
As others have said, this is a job for someone who knows how to use a multimeter, and trace the problem to the source. Will likely take some time, and pulling of all the Tupperware and unplugging a lot of connectors. Having the electrical diagrams for the bike will be just about necessary.

Another thing: Jump starting the bike from a running car is NOT wrong. In fact you WANT the car to be running to supply the full 13.7 volts to overcome resistance in the jumper cables, and supply at least 12 volts to start the bike. I did it several times to my and other's motorcycles. The person who talked about amps knew nothing about electrical circuits at all, period. You could jump the bike from a semi or bus if they are running on a 12 volt battery system. Only the VOLTAGE has to match. The source can be capable of supplying thousands of amps, the device being driven by that voltage determines the amps drawn. Look at it this way: The bulbs in the instrument panel use a fraction of an amp, although the battery is capable of supplying a couple hundred amps for a short time.

The electrical supply into your home is probably protected by a 200 amp breaker, the supply is capable of supplying a thousand or so until the wires overheat. Yet, you can plug in a 4 watt night light, it will not burn out from over current, when what the light it is plugged into is a 15 or 20 amp protected circuit. Same with jumping your LT from a running car. Both systems run at around 13.7 volts engines running, so there is no way any other 13.7 volt supply can harm the bike (unless you hook the jumper cables up backwards!).
 

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You can jump start a motorcycle off any other 12 volt vehicle system, as long as the other system has a larger battery. The LT (or any other bike) will only draw as much current as it needs. You will not harm your system as long as you know how to connect jumper cables. As David pointed out, current flow is dictated by load applied and not by stored energy in the battery.
 

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sounds like an internal short, what is the battery voltage when it is charged - I had a battery acting similar which was 12 volts fully charged, tech told me battery was "dead" and replaced it under warranty, problem solved - it was less than six months old. I have a car battery in the sidecar, like others, to start and run the V Star. I was really surprised to see how small the battery in the LT is - the K1100 has a much larger battery
 

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wkane4 said:
I have what I think is the 170 page manual for the bike that shows everything from unpacking to filling up the tires. It does not include anything about wiring and harnesses. Were do you get that from?
As noted, Clymers has a pretty good electrical section in their manuals. There is also an electrical service manual available from BMW that covers every thing in detail.
 

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Good old "Ohm's", Voltage equals current times resistance.

In the past I heard voltage, and resistance, and current mentioned by themselves so many times that I came to view them as independent entities.

Another mis-concept I made up was that since the plus line was fused, in automobiles, current flowed from plus to minus.

And of course, larger diameter wire had more copper so current had to surmount a larger mass, more resistance.

Bob
 

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Alcanara said:
This is very interesting...... Does this apply to firing up your bike from a car battery (not connected to the car) I.e. the car is not running??

It is 12v of course and capable of delivering mega humph because it normally fires up a 2500 cc diesel. Does the bike simply take what it needs rather than having all that humph!?

Thank you for your help in this matter..... And I hope OP gets his sorted.

Cheers

Stuart
Yes, it applies. The size of the battery is of no concern, just that it is a 12 volt battery. It could be the size of a house, and it would start or jump the LT just fine.

You are correct, the LT takes only what it needs from ANY 12 volt dc source. Even the LT battery is capable of putting out a couple hundred amps easily. It is rated for 19 Amp Hours, which means it will supply 19 amps for one hour, 190 amps for 6 minutes. That is theoretical though, 190 amps would probably overheat the battery in a minute or two.
 

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BecketMa said:
Good old "Ohm's", Voltage equals current times resistance.

In the past I heard voltage, and resistance, and current mentioned by themselves so many times that I came to view them as independent entities.

Another mis-concept I made up was that since the plus line was fused, in automobiles, current flowed from plus to minus.

And of course, larger diameter wire had more copper so current had to surmount a larger mass, more resistance.

Bob
Larger wire has far less resistance than smaller wire. The higher the current (amps) the larger the wire needs to be to keep the wire from heating up.
 
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