R1100GS Electrical Short

R1100GS Dead Battery & Electrical system

Last Tuesday I rode to Atlanta for a social event on my 1995 R1100GS. Afterwards I saddled up and turned the key- for the first time in my experience none of the dash lamps illuminated.We tried jumping off a car- I immediately noticed the cables got VERY HOT. Cables were disconnected and I called a fellow BMW rider and caught a ride to his house. He was kind enough to pull a battery from one of his motorcycles and we returned to my bike. After hooking up a voltmeter to my battery and verifying 0.0 volts we disconnected my battery, then connected hooked his new battery up. Big sparks were displayed when the cables were connected and the voltmeter we had in place showed voltage coming down below 9 volts. All we now know is:

• The battery is dead


• there's a BIG short somewhere in the system

After dropping me at my house I acquired a trailer and retrieved the bike.

Testing begins with properly setting up the testing-

• Removed the tank and connected an ohm-meter across the battery connectors (with no battery installed!)


• Wiggled the cables running in front of the airbox; one cable appears suspicious. The ohm-meter continues to show continuity.

Searching continues- trace the positive battery cables down to the starter and A-HA! There appears to be a short from the cable assembly to the starter housing. Removing the battery cable from the starter and the ohm-meter no longer shows a short.

Repairing the short involves:

• Cleaning the small weld debris located at the corner of the starter.


• Cleaning the connector at the end of the cable.


• Wrapping the cable assembly with electrical tape


• Properly routing the starter power cable around the starter body.


• Oh, and last but certainly not least, a new battery!

Attempts to revive the old battery were not successful. The old battery was a Sealed Lead Acid (SLA) unit; the new battery is an Absorbed Glass Mat (AGM) battery with a slightly higher amp-hour rating.

Everything is reassembled and running well.

Special thanks go to-

• My friend Don for his battery and late-night assistance. I owe you a pizza!


• My neighbor Rod who was kind enough to ride out with me at 3AM into Atlanta to pickup the bike. Couldn't ask for a nicer neighbor!


• My Automotive instructors at North Metro Technical College for their top-notch instruction. Through them I learned not only good theory but also the proper troubleshooting mindset.