R1100RT Motronic Ghosts

[Matt Warren <matt@xxxxxxxxxx>]

Hello all,

I have a ghost in my 97 R1100RT.

29k miles. I spent most of this spring with it on the work stand. This is
what I did:
- Fluids
- Front brake master cyl rebuild, right handgrip w/heat, removed,
re-installed.
- left front suspension bleeder o-seal
- fuel filter
- BMW gel batt
- valve adj, re-sync

The bike ran fine for 1 week. 50 miles/day commuting for 5 days.

I came down one Friday morning, inserted key, got dash lights. When the
starter switch was closed, the bike seemed to suffer massive electrical
load. The dash lights dimmed and flickered, the starter solenoid clacked,
the engine did not turn over. Releasing the button did not clear this
condition immediately but a second later it seemed OK.

Repeated attempts to start got the same thing. Eventually the load was
engaged and never ceased. Now, if the key is turned on, the battery voltage
drops to 2 volts.

I found that either the side stand switch or the kill switch will allow the
ignition to turn to ON with no load. Closing either (they are in series),
causes the load and it does not go away if either switch is opened.

I removed the starter and solenoid, mechanically and electrically. No
change. I pulled the fuel pump fuse (#6), no change. I pulled the Motoronic
fuse (#5), and the condition goes away.

The question now is what in gods name would cause such load that is
controlled by the computer?!? From my read, nearly nothing. Is my computer
shot? Has anyone see on go bad like this? Or has a computer behaved like
this with a poor battery (even though it's new)?

Thanks,
Matt