Elec gremlins/starting probs on GS100

[Deleted Member MS]

A week ago, my GS 100 (93) wouldnt start on the button, but would bump start ok. I put the bike on the optimate, and the battery struggled to charge up, plus 3 cells were dry. I junked the battery and got a new one.
The bike has been ok for a few days but symptoms have started again.
The strange thing this time is that with the bike stould with the ignition on, (engine not running)the headlight isnt on,although the rear light is, BUT the blue highbeam idiot light is lit up (despite the light thumbswitch being in any position, ie, high, low or pass).

Ideas anyone ??

Diode board ??????????? starter relay ????????????

 

[Kenny]

I'm crap at electrics and unless it is a known ( anybody? ) relay fault etc..then obviously I'd start by going over every wire looking for that dreaded short circuit !!

 

[Deleted Member MS]

Aye, just heading for the garage right now.
Any Blue language heard in your area, it'l be me !!!!!!!!!

 

[Deleted Member MS]

Nothing untowards found people. All wires in tact, as is diode board and all earth's etc

Clues anyone ????????????????

 

[SJRoome]

Hi

I think we are going to need more information to diagnose this one.

1. Disconnect the battery and fully charge it.

2. Connect the earth but not the positive terminal to the battery. With no key in the ignition use a multimeter beween the positive battery terminal and the leads that go on it in turn to see if there is any current drain - if there is measure it. Then connect the positive leads to the battery.

3. When you say it wont start using the starter what happens? When you press the starter button do you hear a small click (the starter relay) or a loud thunk (the starter solenoid) or the starter motor and engine turning or nothing?

4. Measure the voltage across the battery and see what it changes to when you hold the starter button in. Put a headlight on and press the starter button - does the headlight dim?

5. Regarding the lights test every light on the vehicle as though you were preparing for an MoT. Which ones work and which dont?

When you report back on that lot we will have something to go on.

Steve

 

[John Armstrong]

And after the above, maybe disconnect and reconnect any plug you can see?

RH forward indicator had a holiday in the rain coming down south on Monday, then worked for a few times and stopped completely. Had a look at the wiring diagram undid a few plugs under the tank near the headstock, and it worked again, but the dipped beam didn't so slashed some WD40 over the pins / sockets, reconnected and it all works

One thing I found out, if an indicator bulb is faulty then if it's the front one that's out, the repeater light doesn't, but if it's a rear one it flashes at twice the rate, just like the repeater light, pity it's not the other way around as you can easily see the front indicator on mine

 

[brassmonkey001]

Check the wires to the back of the ignition switch, I had the green one work itself loose and I could switch the ignition on, lights on etc. but when I thumbed the starter button it did absolutely nothing. I had run a feed off that wire recently so that was where I looked first.
I had exactly the same symptoms* the other day so went back to the same wire thinking it had come off again but it hadn't.

* Apart from on the last ride I noticed the neutral warning light had also stopped working during the ride. I found that one of the wires to the neutral switch had worked itself loose. This is a devil of a job to get back on. Obviously the bike doesn't start if it's in gear and if the neutral switch is disconnected or faulty then the bike thinks it's in gear so won't start.

 

[John Armstrong]

Obviously the bike doesn't start if it's in gear and if the neutral switch is disconnected or faulty then the bike thinks it's in gear so won't start.

I think mine is "different", but DAMHIK

 

[thornley]

Dry battery could well be a result of a voltage regulator on its way out and cooking the battery. Does your battery get hot on a run? Loads of info on here in regard to the voltage regulator if you search. Intermotor brand is same as bosch and lucas all made under license. Part is available from motor factors far cheaper than BMW or usual sources.

 

[Deleted Member MS]

"Connect the earth but not the positive terminal to the battery. With no key in the ignition use a multimeter beween the positive battery terminal and the leads that go on it in turn to see if there is any current drain - if there is measure it. Then connect the positive leads to the battery."
I have a meter, but how do i measure that drop/drain exactly ???

When it wont start, the "noise" is coming from the starter/solenoid, definitely not the relay.

Haviing charged the battery up all day, the bike starts tonight, on the button.
Across the battery terminals, (not running), the volts are 13.2.
When I hit the button, the volts drop and then rise up to and stay at about 14 when the engine running.

Its probable I could go out on the bike tonight, (as it starts ok) but I obviously cannot trust it at the mo !!

 

[(RIP) Proff]

The Volts !!!!

"Connect the earth but not the positive terminal to the battery. With no key in the ignition use a multimeter beween the positive battery terminal and the leads that go on it in turn to see if there is any current drain - if there is measure it. Then connect the positive leads to the battery."
I have a meter, but how do i measure that drop/drain exactly ???

When it wont start, the "noise" is coming from the starter/solenoid, definitely not the relay.

Haviing charged the battery up all day, the bike starts tonight, on the button.
Across the battery terminals, (not running), the volts are 13.2.
When I hit the button, the volts drop and then rise up to and stay at about 14 when the engine running.

Its probable I could go out on the bike tonight, (as it starts ok) but I obviously cannot trust it at the mo !!

Those readings seem about correct to me
Only thing I'd be wary of is the regulator keeping on letting the high charge through when the battery is fully charged,, Your voltmeter pod is your friend.
anything over 14.4 should be viewed warily...
mine is 14 for about 30 mins of running then drops to 13v constant then when I put me lights on it skips to 12 back to 14.4 and settles at 12.5.
If I drop below 30 in top with headlight on voltmeter shows 11 volts, kick her down a gear, open it up and instant charge..
Wonder if I'm ever caught for speeding If I can use the excuse >>
"It was the Volts that made me do it officer"

 

[SJRoome]

Hi

The voltage readings you give are fine.

If it starts on a freshly charged battery but wont start normally it sounds like something is draining the battery. You test the drain as follows. Turn the ignition off and remove the key. Make sure you switched the lights off!

Disconnect the two wires connected to the positive battery terminal. Set your multimeter to a 1A range and connect the black lead from it to one of these wires with the red lead on the multimeter connected to the battery positive terminal. Make sure that the bare part of neither of these wires, nor the multimeter probes touches any metal part of the bike.

Do the same again with the mulltimeter set to progressively lower ranges of current until you either get a reading or you have a range of 1mA or less. Measure any drain on each of the wires you disconnected separately. Then connect them both together and measure the total drain as before.

Now is also the time to tell us about any modifications you made to the wiring or cool accessories you added.


Steve

 

[Deleted Member MS]

Thanks for all advice on this one guys. Turns out it was the rotor. Im back on the road, albeit £50 lighter.

Thanks again

 

[lurcher]

What about the high beam idiot light and the back light prob?

 

[Deleted Member MS]

High beam thing and rear light probs all now sorted since the change of rotor.

Some electrical gremlins I can get my head around. Some others(
the above idiot light thing), I cant !!!!!!