R100RS Electrical Problem Video

monkeybrain

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I posted my problem on here before but have not be able to fix the problem.
First the bike would switch off after it warmed up/ couple of miles riding (total loss of power while riding). In addition some of the indicator lights blew, the rev counter suddenly stopped working and the neutral light bulb in the dash blew. I replaced it but it blew again. Then a brand new Odyssey battery went totally flat within a couple of days.
I have replaced both coils, the diode board and the voltage regulator and had the boyer ignition tested. Put a new battery in the bike and started her up without any problems.
This video is showing the bike being started for the first time since I started trouble shooting. For some reason the indicator light keeps glowing even when off and the red generator bulb which is supposed to go off when revved over 2500rpm goes off when below that and comes on when the revs go up. It should be in reverse. Right? I measured the voltage at the battery and it does charge up to 13.8V when the bike is being revved. Any clue what the problem could be?
Also, when I connected the battery and the bike was turned off I could hear a relay clicking. I thought all the relays would not work unless the bike is turned "on"?

Please have a look at the video and tell me what you think. This is driving me nuts. The only thing I can think of at the moment is getting a new loom and replacing everything.

Thanks for your help!

http://www.youtube.com/watch?v=c4GReUcDRjw
 
You say you replaced the diode board.
- But was it a new one?

My money's on the diode board being knackered though. That would allow the drain when everything is off.
 
1. Diode board that I removed looked like it was in good condition. Replaced it with a used but working diode board. Just in case.

2. The voltage regulator has been replaced.

I just do not understand why the idiot lights are not working properly.
 
The only thing I did was disconnect the kill switch as it was loose and a bit fiddly. No change to the ignition switch.

The boyer electronic ignition was wired according to the wiring diagram. The bike starts well - I think as you can see in the video. That is what I do not understand.

The bike starts and ticks over well but the idiot lights are indicating that there is a problem.

I have disconnected the battery for now as I am concerned that the new battery might be drained again otherwise. The month old Odyssey seems to be wrecked and at 90 quid a pop I do not want to experiment with it again.
 
It's a heavy flywheel bike with the fairing removed so your wirings been modified to remove the fairing harness and move the indicators to the forks. Have you disturbed anything?

Is the new voltage regulator a mechanical or electronic one? all four of my R100s loose the charge light at 1500 and then need to drop below 1000 rpm before it comes back on.

I wouldn't swap the harness yet.

It sounds a bit sluggish when it's revved up - that's something for later though.

Get in touch with Steptoe, he's based in London, works from home and won't rip you off. Might be grumpy though but depends on the time of the month.
 
Mmmh... the indicators have been moved but that was years ago and this only came up recently.
The voltage regulator is the stock BMW one (red box).

How is it possible that the charge light goes on when above 2000rpm but goes off when it is idling? Even though it does charge.

The bike is at Rex's shop (victory motorcycles in camden) at the moment. At the moment he can not work out what is causing the problem.
Geoff Thompson over at the BM forum thinks that I probably have a short or several shorts in the loom or in the headlight. I will check that.

I called Steptoe but he told me that he does not work on R100's. Too old and too much of a pain in the neck apparently.
 
I'm not very good with electical stuff.
Can i ask what year the bike is and can the knowledgable people on here tell me if the wiring system is anything like the one on the ribena bike?
 
As your rev counter appears to not work, I suspect something in the instrument binnacle has gone haywire. Saying that I'm a complete numpty with electrics but something to consider.
 
Have you tried the main Earth connections and the gearbox earth connection etc ..


What relay is clicking when you connect the battery??.
 
ians said:
As your rev counter appears to not work, I suspect something in the instrument binnacle has gone haywire. Saying that I'm a complete numpty with electrics but something to consider.
Click to expand...

I have taken the speedo/rev counter cover apart, checked everything but could not see anything wrong.

To me it appears that something is shorting out somewhere... the coincidence of indicator light bulbs, neutral bulb, rev counter and the battery all dying at the same time.

The annoying thing is that the bike still starts and runs. Would be so much easier if it would not come on at all.
 
monkeybrain said:
How is it possible that the charge light goes on when above 2000rpm but goes off when it is idling? Even though it does charge.
Click to expand...

Steptoes got a point. It's virtually impossible to diagnose electrical problems like this, especially when it sounds like there's more than one fault.

Check the resistance of the alternator rotor. Failing rotors flag up some very strange problems.

These may help

AlternatorTest.jpg


Diodetest.jpg


alternatorquicktest.jpg
 
It can be fun with a loose connection in the alternator rotor; sometimes you get one that ticks the boxes but as the engine spins up, the wire can move away from the connection and the charging stops. Check the resistance as above but also check that it is ok with the motor idling and revved up.
Also, some brushes can just contact when stopped and then lose the contact when the motors running
Are they new? No? Get new ones anyway.
But a half decent bike mechanic should solve it.
I say that as I have done plenty on Guzzis and BMWs. Rob's posted some of the needful...
 
ghiribizzo said:
It can be fun with a loose connection in the alternator rotor; sometimes you get one that ticks the boxes but as the engine spins up, the wire can move away from the connection and the charging stops. Check the resistance as above but also check that it is ok with the motor idling and revved up.
Also, some brushes can just contact when stopped and then lose the contact when the motors running
Are they new? No? Get new ones anyway.
But a half decent bike mechanic should solve it.
I say that as I have done plenty on Guzzis and BMWs. Rob's posted some of the needful...
Click to expand...

Ok, but it charges when revved and indicates almost 14V at the battery. This leads me to believe that the alternator is fine. Changing the brushes does sound sensible though.
 
i think you've got an earth problem somewhere - as indicated by the charging light coming on and the indicators glowing.

double up on all earths and check the diode board earth especially.

also remove the flasher relay as a check - this could be shorted internally
 
Heavy flywheel model you say ........

Check the main relay, it's wiring and contacts under the tank at the front left hand side.

Also the white connector above the top of the engine where the wiring comes out from the timing cover. The connection corrodes in the connector plug.
 
Thanks y'all. I will print all your suggestions and show them to Rex at Victory Motorcycles next Saturday and report back.

Anyone know where I can download a PDF version of the manual for a 1978 r100rs?
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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