It's the Alternator I think..........

[DavidBMWRT]

Enjoyed a beautiful ride to Florida this morning on I-75.
Pulled into a store for a brief stop and when I returned the 2002 BMW 1150 RT died. Nothing. The Tack needle jumped when I turned the key but other than that there was nothing.

All I can figure is that I had been running off the battery for a few days.

The fuses are fine. What do you think?

( I need to add that I gave her a serious bath yesterday, could I have shorted the electrical )

[JimMoore]

You mean no lights or anything, or it wouldn't start?

As a note, if you were running on battery power, you would have a red light on the dash, and you would be able to go about 50 miles.

[DavidBMWRT]

when I turned the key there was nothing but a few brief blinking lights on the dash. As I said the tack needle jumped but other than that there was nothing.
after about an hour the dash lights glowed very slightly.

I turned the key this morning and after a few moments several of the dash lights glowed slightly.

The bike ran great on the trip down the interstate.

[Andy VH]

Sounds like the alternator was not outputting to provide electrical power and keep the battery charged. Could be the alternator belt failed or jumped the pulleys (old Oilheads from 94 did this, I know). Maybe the rectifier quit. Best to get the bike to a dealer, and I hope for you that a warranty still applies. Alternators on the newer Oilheads are NOT cheap at all and can not be rebuilt (unlike the older Oilhead alternator, another reason I like my older Oilhead).

[danielroth]

sounds allot like a simple loose connection in a main circuit.
either at the battery or at the main ground.

[GlobalRider]

What do you think?

Time to stop guessing and get a Digital Multimeter out and do some simple checks.

Get it running (use cables hooked up to a non-running vehicle) and measure the voltage across the battery with the revs up at ~3000 rpm. What do you read?

[GlobalRider]

Alternators on the newer Oilheads are NOT cheap at all and can not be rebuilt.

Why can't they be rebuilt? The one on my 2003 and 2004 oilhead looks like an everyday alternator.

[DavidBMWRT]

Took it to a mechanic this morning. His first guess was a dead battery and I hope he's right but I have my doubts. The battery is three years old. Do batteries just quit without warning?

I'll let you know.

Oh, and he said I had a leaking front seal.........

Thanks for the information.

[GSAddict]

Sounds like the alternator was not outputting to provide electrical power and keep the battery charged. Could be the alternator belt failed or jumped the pulleys (old Oilheads from 94 did this, I know). Maybe the rectifier quit. Best to get the bike to a dealer, and I hope for you that a warranty still applies. Alternators on the newer Oilheads are NOT cheap at all and can not be rebuilt (unlike the older Oilhead alternator, another reason I like my older Oilhead).

Not 100% sure about the Hexheads but all Oilhead alternators can easily be repaired, with regulator/brush assemblies available thru a few sources. Very similar to the Bosch car ones. It's the bearings that are hard to find. That being said the bearings last a very long time if the belt is adjusted properly.

I "hopped" mine up for a 14.6 volt output to compensate for the AGM requirements of my Odyssey battery. Never have to put a charger to it to fully charge the battery.

[norton]

Do batteries just quit without warning?

Yes, especially the BMW Gel.