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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: AussieBrick on May 29, 2015, 10:33:09 PM

Title: K1100LT '93 - Battery slow discharge while engine running - ABS fault
Post by: AussieBrick on May 29, 2015, 10:33:09 PM

Hi All, My first post here on Motobrick so please be gentle :-)

Bike is BMW K1100LT 1993 (probably ex Police bike).

Background. I bought a handful of these bikes from a friend. This is the first to be looked at.

The first job is just to get this one running in basic mode. The first identified issue is this.

Problem: Discharge of battery while engine is idling (or on slight 'choke').

It is fitted with a brand new charged battery (correct spec). It starts fine. Runs fine (idles etc).  After fiddling with it for a while, while it was running, I went to restart it. Battery was dead. Short story is that although the 'Battery Charge Light' goes off, putting a voltmeter across the battery terminals shows a steady drop of the battery voltage.

For the heck of it I removed the alternator and give it a service. Cleaning brushes, rings etc., even though the indicator light implies it is fine.

Digging around a bit more I found that if the ABS control unit is unplugged, the discahrge issue completely goes away and the alternator charges well.

So....As I am no electrical genius and new to these bikes, any help would be appreciated in how to further diagnose the ABS fault (causing battery discharge).

Thanks in advance.

Title: Re: Battery slow discharge while engine running - ABS fault
Post by: johnny on May 30, 2015, 08:25:52 AM

greetings aussiebrick...

first thing i would do is putts a meter on the abs connector you removed from the main wire harness... check each wire for continuity to ground and between themselves... look at the wire diagram to see which one is whack and go from there...

j o

Title: Re: Battery slow discharge while engine running - ABS fault
Post by: gazman on May 30, 2015, 10:40:12 PM

Greetings from fellow Aussie Bricker, I cant help with your problem. . . . . . but this forum most certainly can. A handful eh? maybe you can hook me up with some parts down the line. Again welcome, enjoy.

Title: Re: Battery slow discharge while engine running - ABS fault
Post by: AussieBrick on May 30, 2015, 10:56:49 PM

Johnny. Many Thanks I will try this out (hopefully without frying myself or the bike).

I am sure the problem is in the ABS, it is just a case of whether the issue is in the control box or one of the two relays I suppose.