Brake warning light and current drain, R1150RT

[Bill_Walker]

Yesterday, I planned to ride my 2004 R1150RT. I unhooked the battery tender, which had shown it was in float mode. Turned on the key so I'd have brakes while pushing it out of the garage, and the brake warning started flashing quickly, with a whine from the ABS pump, and didn't stop. The general warning light was off. I tried cycling the key a few times, but no joy. Ended up having to admit to my Harley-riding bro-in-law that my RT wasn't up for the ride, and took my other bike.

 

Today I'm starting diagnosis. I hooked up my never-before-used GS-911. Realizing I'd have the key on for a while, I turned off my fog lights and aux lights, which I normally leave on, and turned on the key. No fault. Hmm. I finally found that I could make the fault occur or not depending on whether or not my PIAA 1100s were switched on. Odd, since the battery is fully charged and I have ridden nearly 50,000 miles with these lights, hardly ever switching them off.

 

So, before I start pulling tupperware, I thought I'd check my guesses here. First guess is that I should clean the battery terminals. Second guess is that it's time for a new battery, despite the BT showing a full charge. Hmm, just double-checked my records, and unless I forgot to write a replacement down, that's still the original battery! So there's a likely contender.

 

The lights are working, so I don't think there's a cut wire or something.

 

Anything else I should be checking? Any tips on a replacement battery while you're here (I'll be searching on that, too. Tried searching on this and didn't find any posts with the same symptoms).

[Bill_Walker]

P.S. The GS-911 showed no current faults, but did show a past fault of a voltage dip, and several of disagreements between processors.

[Bill_Walker]

I think I must have replaced the battery in 2007 without writing it down. The current battery is a Panasonic LC-X1220P. I have an e-receipt from August 2007 for a battery with the same capacity, but the receipt uses the vendor's part number. Still, at over 4 years, it might be getting to be time.

[Alfred02]

easiest way to test it is by hooking up a car battery with jumper leads to your existing battery.

A battery can break down under load, despite that it comes up to full voltage when not in use or the engine is running and the Alternator is charging the battery all the time.

[dan cata]

+1 for a battery fault.

 

Dan.

[AndyS]

Is the brake light on at the back of the bike? check your brake levers - listen for the click of the microswitches. You may have on that is jamed on (likely to be the rear brake lever microswitch with a tiny stone jaming the leaf into the energised position).

Andy

[dirtrider]

Morning Bill

 

A quick guess would be low battery voltage (especially given your PIAA's being on effecting the problem).

 

A very simple test would be to simply start the engine. Running engine with alternator output should raise the system voltage. If the engine cranks over easily & with the engine running the brake warning problems goes way then it is/was probably low battery voltage.

 

The ABS system monitors it's supply voltage & if not enough to properly operate the pump for a full ABS event it will put the brake warning light on & disable ABS. (common problem on I-ABS equipped motorcycle police training ranges after repeated low speed brake usage)

 

 

[Bill_Walker]

Is the brake light on at the back of the bike? check your brake levers - listen for the click of the microswitches. You may have on that is jamed on (likely to be the rear brake lever microswitch with a tiny stone jaming the leaf into the energised position).

Andy

 

Nope, no brake light on, or brake light failure. Both brake controls seem normal.