Re: R1100RT Motronic Ghosts

[Matt Warren <matt@xxxxxxxxxx>]

>> Hello all,
>> 
>> 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)?
> 
> Matt,
>    Are you sure the battery is good?  Some of the BMW GEL batteries had an
> early end of life. :)

It was purchased last fall from Max BMW in NH and never put into the bike
over the winter. I put it in during my extended service time this spring. It
has 1 week of actual use. Though, yes, it could be a bad apple.

>    The Motronic is the only component left that is powered via F5.
>    When you pulled your starter, did you test it by spinning it with a battery
> and jumper cables?

I havn't yet. But once it was removed and the problem still existed, I
figured it was moot. But I'm getting some cables to test it on a bench
battery.

> 
> Mick
> Tucson