'11 RT Intermittent alternator

[kltk165]

Hey folks. This is going to be a bit long, so, please be patient. Strange problem, not entirely sure where to go with this. Started the bike last week and took it for a short ride. Red triangle and battery lights came on. Was between exits and had to travel about 16 miles before getting it back home. At stop lights bike idle was going crazy up and down. Also had a brake failure light come on and the defective bulb light come on. As the battery is 5 years old I assumed it was the battery and replaced it. Installed a PC680 per Odyssey instructions. Voltage at time of install was 12.7 volts so I did not charge it prior to starting the bike. Started the bike and the battery/Red triangle are still displayed. Took it for a short ride to see if it might clear and about 10 minutes in the light went off. I made the assumption everything was probably OK and went riding. I made three stops before reaching home. On restart after the first stop the Red Trinagle/Battery lights came on for a few minutes but went out. Second stop, same thing. Last stop the light came on at restart and did not go out and remained on for about 20 miles to my house. Near home the bulb and brake failure lights came on. Idle was fine. Checked battery voltage and it was down to 11.91. Not knowing if it was the battery or the alternator, I removed the battery and bench charged it with a Battery Tender Plus. I left it overnight and checked it at 9:00 AM this morning. Battery Tender light was green and I got 13.13 volts. Checked again at 11:00 AM voltage is at 13.04 volts. Checked again at 5:00 PM, voltage is at 13.01 volts. Please correct me if I'm wrong but, it seems like the battery is OK.

 

I reinstalled the battery and voltage remained steady at 13 volts while connected to the bike. Started the bike, red triangle and battery lights are OFF. Voltage measures 14.07 with the bike running at idle. Turned the bike off, voltage drops to 13.16. Let it sit for a few minutes and start up again. Red triangle/battery lights are ON voltage shows 12.66.

 

Something is clearly going on with getting voltage to the battery, before I start buying and replacing parts, I want to rule out any possible computer related problems. Is it possible with all the flags being thrown there are errors that need to be cleared? If I simply wasn't getting voltage to the battery I think it would be safe to assume the alternator needs to be replaced. It's the intermittent on/off that has me concerned it may not be a simple alternator swap. Thanks in advance for your assistance.

[dirtrider]

Evening kltk165

 

 

That is a strange one indeed.

 

I guess the place to start looking is to remove the front belt cover & make sure the belt in intact & not shredded or slipping.

 

Then start the engine a few times & make sure the alternator center shaft is also spinning (not JUST the outer pulley but also the center shaft)

 

If all OK there then make sure the red wire connection at the rear of alternator is tight on the rear of alternator.

 

If still nothing found then see if revving the engine will start it charging again next time it shows a no-charge condition.

 

The ZFE module does initiate the charge sequence but that is only the start of charge so usually revving the engine a bit will start the charging sequence regardless of ZFE input.

 

Otherwise you might need to get a GS-911 on that bike to check for failure codes or remove the alternator & have it FULLY tested.

 

It sounds more like a loose connection somewhere (probably large red wire) or a slipping belt/pulley issue.

 

It doesn't point directly to a failing alternator but don't count that out.

[James L.]

It sounds like bad brushes to me. This happens when the brushes get worn and do not stay in constant contact with the armature (brush jumping). Typically not a job the average person can fix, but people who are very motivated can replace the brushes if they can find the replacements.

 

James L

[kltk165]

Excellent. Thanks guys...

[kltk165]

Quick update. Today was the first chance I've had to do anything with the bike. I took the body panels off today and tried to look in there, but, as those who wrench know, you can't see much with the fuel tank on the bike. As I've never taken the tank off, I didn't want to take on that task today.

 

However, just for the fun of it, after buttoning up the bike I fired it up just to see what would happen. Triangle light went out immediately. Let it idle for a minute to see if it would come back. It didn't. Turned the bike off waited a minute and fired it up again. Again no light. Rode the bike around my complex (<20 mph), parked the bike and let it sit for about 5 minutes. Brought out the multimeter to see what that looked like. Battery was at 12.9 volts. Fired the bike up and again the triangle went out immediately. At idle multimeter settles in at 14 volts and tips up to 14.07 for a minute before coming back down to to 14 volts. Did a little research and it seems that's right about where the voltage should be at idle with a working alternator.

 

Was very happy with the results, not happy not knowing what the cause was. Shut the bike down, suited up to give the bike a proper test ride. Fired up the bike, light goes out immediately and stays out for the 40 minute 20 mile ride. I stop and let the bike sit for 20 minutes. Hop back on, fire it up and there's the triangle and battery lights. Stayed on the entire 20 mile ride back home. Tomorrow I'm calling a local BMW Tech to see if I can bring the bike by to get the codes from all the flags being raised. I'm also going to get the front cover off to see what's happening with the alternator belt and armature. I removed the battery to bench charge it as the battery was used up by the time I got home (11.9 volts). And to absolutely rule it out, I charged the battery for a couple of hours then took it to my local Batteries Plus for a shake down. The battery came back good. So I can now rule out the possibility I got a bad battery.

[kltk165]

Here's today's update. I noticed yesterday the when the bike is cold, the light will not come on and the battery charges. I started the bike a few times yesterday letting it run for about a minute, shutting down for a minute then restarting and it was fine. It was the first attempt of the day. Again thinking everything was OK all of a sudden, I went in to suit up only to come out, fire it up and the light was on. It seems as though the problem occurs when the bike is hot, however, it doesn't happen if the bike is started and left running. Only if you stop the bike then restart it. That was yesterday.

 

Today I took it to a dealer to get the codes that were trapped and it looks like there were several. As I was expecting because of all the starting and stopping I was doing. I can't make any sense of it. The dealer felt confident it's the alternator. Thoughts?

[dirtrider]

Morning kltk165

 

 

On your alternator & fault codes?-- most of those fault codes are the result of low system voltage

& none point to what is actually wrong with your motorcycle charging system.

 

You definitely have a charging issue but there is no way to tell from those fault codes IF it

is a failing alternator, or loose wire somewhere, or slipping belt, or ?????. (basically those

fault codes tell us that it isn't/wasn't charging correctly at times but doesn't tell us why it

isn't charging)

 

A good technician will (first) eliminate the easy stuff like alternator belt, bad alternator

pulley, or loose wire, etc-- then if nothing obvious probably repair/replace the alternator (or at least

remove it & have it FULLY tested).

 

[kltk165]

Well, the worst case scenario has played itself out the last few days. Sunday, knowing the bike would be fine as long as I don't have the warning lights, I decided to take the bike for a long ride without shutting it down to see if the problem showed itself. I rode 2 hours nonstop, no warning lights. Arrived home, shut the bike down and let it sit about a minute and restarted. No warning lights. Shut it down, waited 15 minutes and restarted. No warning lights. Let it sit the remainder of the afternoon and restarted. No warning lights. Tuesday I decide to just ride the bike normal locally to see what I get. Attached a multimeter to see what's happening as I'm riding. Covered 200 miles of every type of riding I typically do on a day out. Some tooling around town, some high speed twisties, some interstate, some simple backroad riding. Stopped and started the bike numerous times throughout the day. No warning lights and I'm getting a consistent 14-14.10 volts throughout the day. Temps on Sunday were in the upper 60's and partly cloudy, yesterday we were in the low to mid 80's and sunny. Stopped by the dealer today to chat about what was done while it was there Saturday. The only thing they did was clear the codes. I asked if it's possible the ZFE would have, or could have been, reset in the process. They said no. And there's no way it can be reset/rebooted. It works or it doesn't. Again, that's what I was told. If that information is not correct, please correct me. Also, is there any way of testing the ZFE? Could an alternator repair facility test this part?

 

As we all know this is a worst case scenario as there's now a confidence problem. Something is going on and it simply went away. The only change has been the dealer clearing whatever fault codes were in the system. Fortunately, I don't have any trips planned the rest of the year so I'm not too troubled and at some point over the winter the alternator will come out and taken to an alternator repair facility to see if they see anything ugly going on. I hope they find something to be honest.... Thank for your help DR, as always you're a great resource and incredibly kind...

[dirtrider]

Well, the worst case scenario has played itself out the last few days. Sunday, knowing the bike would be fine as long as I don't have the warning lights, I decided to take the bike for a long ride without shutting it down to see if the problem showed itself. I rode 2 hours nonstop, no warning lights. Arrived home, shut the bike down and let it sit about a minute and restarted. No warning lights. Shut it down, waited 15 minutes and restarted. No warning lights. Let it sit the remainder of the afternoon and restarted. No warning lights. Tuesday I decide to just ride the bike normal locally to see what I get. Attached a multimeter to see what's happening as I'm riding. Covered 200 miles of every type of riding I typically do on a day out. Some tooling around town, some high speed twisties, some interstate, some simple backroad riding. Stopped and started the bike numerous times throughout the day. No warning lights and I'm getting a consistent 14-14.10 volts throughout the day. Temps on Sunday were in the upper 60's and partly cloudy, yesterday we were in the low to mid 80's and sunny. Stopped by the dealer today to chat about what was done while it was there Saturday. The only thing they did was clear the codes. I asked if it's possible the ZFE would have, or could have been, reset in the process. They said no. And there's no way it can be reset/rebooted. It works or it doesn't. Again, that's what I was told. If that information is not correct, please correct me. Also, is there any way of testing the ZFE? Could an alternator repair facility test this part?

As we all know this is a worst case scenario as there's now a confidence problem. Something is going on and it simply went away. The only change has been the dealer clearing whatever fault codes were in the system. Fortunately, I don't have any trips planned the rest of the year so I'm not too troubled and at some point over the winter the alternator will come out and taken to an alternator repair facility to see if they see anything ugly going on. I hope they find something to be honest.... Thank for your help DR, as always you're a great resource and incredibly kind...

 

Evening kltk165

 

The ZFE can't be reset but can be re-booted & codes cleared (doesn't change anything). Not that it would help as the ZFE DOESN'T control the alternator. The only thing the ZFE does is supply a small current to the alternator to start it charging but once the engine is revved up it should start charging by itself even without that initiation current from the ZFE.

 

As far as testing the ZFE?- no real way to do that at home or at dealer level. Possibly sending it to BMW development engineering they might be able to test it (IF) they have a simulator set up to run the ZFE for bench work.

 

I'm still not sure what your problem is/was but it sounds like what the dealer did should not have changed the alternator operation.