K100LT Electrical Problem ??? [Archive]

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Warthog

09-12-2006, 06:40 PM

I took my bike out for a spin today and when I stopped at drive thru teller I turned of the bike with the kill switch but left the ignition on. After a minute or two I attempted to start my bike and everything was dead. Since I was several miles from the house I push started the bike and headed home. Along the way I noticed that the ABS light and the warning light (one with the triangle and !) were blinking. I also noticed the turn signals were not working. I was getting power from the accessory plug as my XM radio was working.

When I got home I listened to the engine before shutting here down and noticed what sounted like a grinding noise from the starter/ alternator area. When I shut down the engine it sounded as if the starter was trying to turn over even though the kill switch was off and the key out.

Any ideas???

deilenberger

09-12-2006, 07:24 PM

DISCONNECT YOUR BATTERY! The grinding noise isn't a good thing, and eventually could result in some badly overheated components, which could result in a fire.

You have a stuck starter relay. This is usually caused by trying to start the bike with a very weak battery. The relay lives in the Ebox under the tank. Choices are hit it to make it release, or replace it. The points on it are now burned from arcing due to the low voltage and incomplete "pull-in" of the relay by the low battery.

Then invest in a new battery. Sounds as if your old one is toast.

Warthog

09-12-2006, 07:58 PM

When back this evening and turned the bike on to see if the turn signals and headlight worked and they did so I attempted to turn the bike over. Had a very weak turn over which makes me think the battery is toast. I pulled it and check the fluid levels and they were ok. It is a BMW battery and is a little over a year old. I just checked the voltage and it is sitting just shy of 12 volts.

Should I replace the starter relay and attempt to reuse the battery?

deilenberger

09-12-2006, 08:15 PM

Don,

Unless you can find a reason the battery is so low - it may just be a faulty battery. You might check with the dealer you bought it from as to the warranty.

At worst - I would want it on a battery charger overnight (one that automatically shuts down so you don't cook the cells.) and would want to see > 12.6V on the terminals after you let the "float-charge" dissapate (let it sit for about 1/2 hour after coming off the charger..)

Then you might try starting the bike. Since it recovered a bit - it sounds as if the relay isn't stuck anymore, so you probably have dodged that bullet.

If you were doing a lot of around-town-toodling-around, with lots of starts and stops, and little high RPM riding - it is possible to run down a K bike battery. BTDT, learned to avoid doing it again.

Kayseventyfive

09-12-2006, 11:58 PM

Give it a nice slow charge and read it with a hydrometer. Then let it sit disconnected for a day and read it again. A year old battery should read 1.260 each time.

gadwal

09-13-2006, 10:05 AM

Don,
I had the exact same problem with my K100LT last month; turned out to be a bad battery. Check my thread (gadwal) posted a few weeks ago, as there were several very informative relpies.
Bill

Warthog

09-14-2006, 10:35 PM

Well, I disconnected the battery, pulle the starter relay tapped a couple of times and replaced both back on the bike. I then charged the battery overnight and it started up in the morning. Took off for work and noticed the abs light and the triangle ! light were flashing. I pushed the ABS reset switch and the both went solid for a while and then came back on flashig. Got to work and when I came out there was a very weak battery. I eventually managed to get it to start. Rode to an appointment and for awhile no flashing lights then they kicked on again flashing. Althought the battery light is no coming on I am begining to believe either the battery is bad or the alternator is going bad.

Its back on the charger and I will pull it this weekend and take it into the dealer to have the battery checked.

deilenberger

09-14-2006, 10:55 PM

Don,

The ABS fault lights may be coming on due to low voltage. There is some speculation that eventual ABS brain failure (expensive) may be caused by repeated incidents of low battery voltage..

It sounds like a bad battery - but also given the symtoms could be some load on the system when it shouldn't be (when the switch is off). Unless you have some skill using an ammeter, and have one to use - I'd suggest visiting the dealer at this point. Hopefully they have a battery load tester which will tell you in very short order if the battery is KAPUT (tech-term.)

Warthog

09-14-2006, 11:07 PM

Thanks Don, I had the bike in for service after I bought it and they recommended indicated I needed a new battery along with a new clutch and rear main seal. That was a little over a year ago.

I ride about ten -15 times a month normally but this summer we have had a rash of afternoon thunder storms and I have not riden as much to work. Especially after the guy in Dever got struck by lighting while riding his bike down the hiway.

I also don't tend to keep i on a charger either. Wonder if that may have caused the battery to have gone bad?

I also recently had my headlight switch go bad. I pulled it apart and cleaned it according the articles on " the other BMW site".....working ok but still has a dead spot.

DarkCloud

09-15-2006, 12:38 AM

Warthog

09-15-2006, 06:08 PM

Dropped into my local dealer and they popped said battery into the load tester a low and behold one cell was shot. They were about to sell me another battery when I popped the question "Is this under warranty?" the reponse was only if we installed it. Fortunately, the battery was installed when I had all the work done last year on the rear main seal.

Now here is the weird part. They pulled up the orignal invoice and they had my bike listed as a K1100LT vice a K100LT and the battery part number did not match they battery I had. The battery I had was thinner than the battery that they said they put in. They are going to replace it under warranty with the bigger battery. Hopefully that will fix the problem.

deilenberger

09-15-2006, 07:08 PM

Don,

I thiink your problems will be resolved with the new battery..

Good to hear!

:buds

PHMarvin

09-15-2006, 09:32 PM

Hi, Don Burns,
Back in '84 when the K100/RS/RT were about to appear in the US market, I had occasion to look at an option sheet from an European dealer for the K100RT. The standard battery was the "small" battery with the "big" (28a/h then, since reduced to 25 a/h) battery optional. The "big" battery would fit the K100 and K75 bikes as well as the '93 K1100 bikes. The advent of ABS II spelled the end of the "big" batteries in the K1100 bikes. Your K100LT should be fine with the 19 a/h "small" battery, although, given the choice, I'd rather have the "big" battery. I have a 25 a/h battery in Harriet's K75(ABS).

Warthog

09-16-2006, 09:05 PM

Well, I picked up the battery this afternoon and it was the large 25a on and it fit perfectly in the bracket. Took her out for a shakedown ride and and so far no problems. Thanks to Colorado Springs BMW for standing behind their work and reconfirms my decision to buy locally event though it might be a little more expensive.

Thanks for all of the advice / help on this topic. Thankfully, I did not have to replace the starter relay....

PHMarvin

09-16-2006, 10:53 PM

Hi, Don,
Eurocity Cycles (I think that is the name of the Colorado Springs BMW dealer) is one of the better BMW shops. If it weren't almost 600 miles from me, I'd take my bike there for work I couldn't do. And besides, Matt Parkhouse works there!

Warthog

11-20-2006, 01:13 PM

deilenberger

11-20-2006, 01:26 PM

A word of warning - since it's likely you have ABS-I - you do not want to have low battery voltage with this system.. many failures of the ABS brain appear to be related to a low-voltage condition. That's a bad thing since the brain is very expensive to replace.

Just a FWIW - I'd try to solve the problem as soon as possible.

wmubrown

11-20-2006, 07:37 PM

Was riding home the other day and had the Triangle light and ABS light start flashing again. I pushed the rest button and they went solid for about ten minutes and then went back flashing.
That's all it's meant to do.

Got home and parked the bike on Friday and came back on Sunday evening and attempted to start the bike and the battery was ery weak. I stuck on the battery charger and will check again when I get home.

The battery is a new BMW battery that I replaced awhile ago and I'm starting to wonder if I have a problem with my alternator and it is not charging the battery.
A low battery will prevent the ABS system from properly initializing. My K1100LT was doing this until I put a new battery in. A good test is to start the bike, if the ABS faults ride it for 10 minutes or so then turn the bike off, wait a few seconds, turn it back on and start it - if the ABS initializes you have a weak battery - if it continues to produce a fault, it could still be a battery but you might have other problems...

Warthog

11-22-2006, 06:01 PM

Ok, my analog VOM crapped out so I had to purchase a new one and Radio Shack only had a digital one. Read how difficult it was to read out the fault codes with the digital so I went the LED solution. Radio Shack had a red LED assembly that came with a built in resistor (part # 276-270) so I thought I would gave that a try. It is a 12V 12mA LED but does not list the Omh on the resistor.

I first checked the battery and it was 12.18 volts. Next I did the fault code read out and the LED went a steady red and after a couple of seconds it blinked five times and stayed solid on the sixth time. I am interpreting this to be a fault code 5 which suggests a low voltage problem.

I have attempted to reset using the 8, 20 , and 60 second method to no avail.

Given the battery voltage and ideas? The battery is only about a month and a half old.

The only modification I have made to the electrical system was to add some driving lights which are wired directly to the battery. It has a small lighted switch and I only use them occasionally.

deilenberger

11-23-2006, 12:57 AM

I assume the battery reading was without starting the bike? 12.1V/12.2V is a sign the battery is about 40% discharged. A good battery will read 12.6-12.8V after charging fully and sitting for 30 minutes or so.

The low voltage will drop much lower when the starter is operating, which is what is causing your low voltage ABS faults. As I mentioned before - there is some evidence that repeatedly doing this causes failure of the very expensive and non-repairable ABS brain. You don't want to have to replace it.

You're either not riding the bike enough (in which case I'd keep it on a BatteryTender), or there is some draw on the battery with the ignition off that is pulling it down, or you have yet another defective battery.

I'd guess against the last. So that leaves the others.. If the meter you bought has a 10A current scale - lets take a look at the ignition off battery draw. Disconnect the ground wire for the battery where it fastens to the transmission, and connect the meter between the ground point and the ground cable. It should be set to Amps BEFORE doing this.

We're looking for the current draw by the bike ignition off. I would expect it to be less than 100mA (1/10A).. more than that indicates something is wrong. The meter will likely autorange and display the draw in mA..

If it is 100mA or less - that leaves the other possibility - that you need to ride the bike more/longer/higher-speeds, or buy and use a BatteryTender.

I'm a cheap guy - so I just ride my bike as much as possible to keep the battery charged up. When I can't - I do monitor the battery voltage and charge it when necessary.