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Topic-icon '79 R100RT: EME charging system and electrical gremlins

  • penguinworks@shaw.ca
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3 weeks 6 hours ago - 3 weeks 1 hour ago #6799 by penguinworks@shaw.ca
'79 R100RT: EME charging system and electrical gremlins was created by penguinworks@shaw.ca
I installed an Euro Motorelectric EnDuraLast II Charging System. The problem - Once the battery is fully charged, the voltage drops on the voltmeter about ½ volt and the generator light (Katdash LED bulb holder) starts to glow getting brighter until the voltage drops ¾ - 1 volt and then the generator light would go out, it charges back up and then repeats.
Note:
• When installing the system the EME variable voltage regulator was damaged. Plugged it in to set the voltage but when I attempted to unplug and mount it the connector pulled loose. I ordered a new one (EME charge postage only) and put my Hella voltage regulator back in. Everything worked for the first 500 k then the problems started.
• The generator light seems to go on and start to charge again when shifting or RPM changes.
• When the battery appears to be getting close to charged and you rev up to 5000 rpm the generator light comes on (weakly) then goes out when you back off.
• When it’s not charging and you idle the generator light pulsates.
• If you shut the bike off for any period of time it’s charging again when you start it.
• Initially this problem was intermittent but now it does it consistently.
• Everything else in the electrical system works fine.

Actions taken so far:
• Replace Hella voltage regulator with EME variable voltage regulator.
• Replaced EME diode board. (and went through entire charging system checking every wire and connection with a meter for both shorts and connectivity)
• Replaced Battery
• Replaced Voltage regulator wiring harness. This was the only part of the charging system wiring that wasn’t included with the EME charging system. (and went through entire charging system checking every wire and connection with a meter for both shorts and connectivity)
• Installed a 330 Ohm resister between switched power and D+ wire between the voltage regulator and diode board. (EME work around for gen light issues)
• Replaced EME voltage regulator with Hella.
None of these actions made any difference.

I don’t think it’s the Katdash as the 330 ohm resister didn’t make a difference.

The problem could be heat related as it never happens when the bike is cold (though that could be because the battery is discharged starting the bike) . Heat and RPM makes one suspect the rotor. I’ve had rotor failures in the past and it acted much the same way. Can I put the old rotor back in – is it compatible? The stator and rotor are the only things I haven’t replaced.

So far its never quit all together but it does get nerve racking. I carry a battery charger with me in case I have to stop and find a plug.

I’m getting tired of taking this bike apart and putting it back together. Causing wear on all the fasteners. I kept all the old parts so perhaps I can salvage the old charging system and put it back in ( It actually generated more power as it ran 100% of the time, not 50%). I don’t know of any other way to determine if it’s one of the EME components.

Any suggestions?
Last edit: 3 weeks 1 hour ago by Wobbly. Reason: Mods altered title

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3 weeks 5 hours ago #6800 by 8166
Have you checked your brushes? Both for length and good connectivity?

Have you tried shorting the two outer wires in the VR plug? Doing so should result in a voltage higher than 14.5V at higher RPMs for as long as you hold the RPMs. Don't leave it that way for long, as it's hard on the battery and various bulbs. But if you see the voltage varying the way you describe with the jumper in place, it's not the VR.

It's not unusual for the VR to be bad; I can't imagine any other component in the system that would produce the symptoms you describe, except perhaps the brushes.

Not sure how the KatDash handles the charging light, but if they've substituted a diode fpr the old fashioned filament bulb that is stock, I don't see how it could work properly. Current flow through a diode can be one direction only, but current flow through the bulb in actual operation can be in either direction.

If your brushes are OK, what does EME say? Unfortunately, I've heard many reports of them blaming everything under the sun except their components when something goes wrong.

Have you tried going back to your old rotor and stator, leaving the EME VR and diode board in place?

8166 Scot Marburger, This email address is being protected from spambots. You need JavaScript enabled to view it.

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3 weeks 2 hours ago - 3 weeks 1 hour ago #6802 by penguinworks@shaw.ca
Replied by penguinworks@shaw.ca on topic '79 R100RT: EME charging system and electrical gremlins
Forgot to mention 1979 R100RT

Checked brushes - they were new ones supplied with the charging system. I even re-soldered the connections. From what I understand Katdash has resisters to supply power to the rotor independent of the led. It worked fine with the old charging system.

I have discussed the problem by email with EME and many of the actions I've taken were their recommendations. I just sent them a update and was waiting for a reply. I was going to try the old stator/rotor. I don't believe i can use the old rotor with the EME stator so I'll have to change both.

I'll try the jumper on the VR plug and see what happens. I've got 13.8 V at the battery and tried two different VR's. And new VR wiring harness
Last edit: 3 weeks 1 hour ago by Wobbly.

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3 weeks 1 hour ago #6803 by Wobbly
• Can you give some more background, please. Why was the alternator upgraded to begin with ? It sounds as if the old unit was working OK if you are willing to re-install it.

• So the way I read this is that the Hella VR is on there currently. What battery are you using ?

• Do you run a headlamp modulator ?

• What other mods have been made to the electrical system ?


On the face of it, it sounds as if you need a replacement VR. My Hella VR burned up within about 9 mos on a completely stock system. I counted it as a fluke and replaced it with an adjustable version, which I had to install anyway due to my new AGM battery. (AGMs like a slightly higher voltage than the older "wet cell" batteries like the OEM.) Now I see Motorrad Eliktrik sells a fixed (non-adjustable) version for AGM. This is why I'm asking you to ID your battery type.

Hope this helps.

Don't hide 'em, Ride 'em !!
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2 weeks 6 days ago #6805 by penguinworks@shaw.ca
Replied by penguinworks@shaw.ca on topic '79 R100RT: EME charging system and electrical gremlins
Why upgrade the charging system? I'm asking myself the same question. I had installed the Hella VR and Thunderchild diode board years ago. I needed to replace some of the wiring (the B+ vibrated loose), new brushes and was going to buy a backup rotor. I had also added a couple of aux plugs and my heated vest doesn't seem to get very warm (I'm in Canada) so I thought I would just buy the new system (was about the same price)

I had an original BMW battery. I replaced it with a sealed unit - Yuasa GYZ High Performance Factory Activated AGM Battery. No headlamp modulator. The only other mods to the electrical was when it was double plugged 30 year ago - Andrew coils and Dyna ignition booster.

I'm going to recheck the voltages today and try to bypass the VR and see what happens. The problem is whenever I test things everything is working. 20 - 30 Km down the road it stops charging. If I turn around and head back by time I get home everything is working again. It could be the VR but I didn't think two of them would fail the same way. I'll check out Motorrad Eliktrik.

Thanks for the help.
Kevin

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2 weeks 6 days ago #6806 by 8166
FWIW, I replaced the charging system on my '95 RT with a 600W Omega system from Motorrad Elektrik. At a tech day, Snowbum and I load tested it to 1000W, but typical loads will get nowhere near that. I ride all year round, and the RT is my weapon of choice for longer trips to Southern California ABC Rendezvous. I've seen temperatures as low as 23F on these trips, and it's nice to know that there's plenty of juice available for heated grips, heated jacket, a pair of HID driving lights, and plenty of electrical gadgets. It's also nice to know that there are parts available for the Emerald Island charging system, overnight if needs be, from any one of several EI vendors.

From your description, now the problem seems like it might be more mechanical in nature. If you had to reuse the stator housing, are you sure you got the insulator stack installed correctly? There should be no conductivity between any of the threaded studs and the housing itself. Wiggle the wires attached to those terminals vigorously when you check for continuity, there may be something loose or improperly installed that would result in an intermittent condition that you describe.

8166 Scot Marburger, This email address is being protected from spambots. You need JavaScript enabled to view it.

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