B**** micro switch

[Barrmill Biker]

I am now ready to pull out my hair
the micro switch at the back of the
front break leaver was knackered so
after a few problems managed to get replacement
fitted said replacement all working fine
came to work this morning stopped by a
friendly police man who told me my brake light was on
all the time and could I get it sorted A.S.A.P
he was very friendly about it and even offered a few suggestions as to the
problem. Got to work to find the switch
at the break lever is the problem again
it isint sitting right any suggestions
or has any one had similar problems?

 

[unhinged]

You may be well aware already but you can adjust the point where the microswitch triggers by adjusting it with a little screwdriver. On my 1150 (I don't know whether they've changed) this can be done looking up from underneath the controls. Mine was doing the same and just needed adjusting.

 

[Barrmill Biker]

Micro switch

Do you know if it's the same on the 1200 and many thaks for the
info will get a look at lunch time

 

[unhinged]

I've not idea but I'd be suprised if they're not adjustable in a similar manner if they aren't the same. On mine you can hear the switch activate and by sticking a tiny screwdriver in the slot underneath, the point of activation can be changed. Obviously if the brakelight's on you won't hear the click.

 

[Barrmill Biker]

The on going saga

Spent my lunch break checking the micro switch
and guess what it's working but the b*** break light
is still on I think its a trip up to the boys at the garage
don't like driving without my ABS got to used to it now.

 

[unhinged]

Well, the other problem I've had was putting the rear bulb in round the wrong way which meant that the both elements in the bulb were lit regardless of braking. Have you changed the bulb lately?

 

[Barrmill Biker]

microswitch front breake lever

Good thought but havent changed the bulb
but will take a look at the back light just
in case.

 

[Nate]

mine got a bit smashed up when i dropped the bike last year

All I did was pull it out to find that the switch had moved under the impact of the brake lever...

You can put the screw in and move it about a bit till its in the right spot and then screw it up tight

Hope you get it sorted soon

 

[araspitfire]

I've found that rigging the front brake switch is pretty easy... Just adjust it till you hear the little click at the slightest movement of the brake lever...

It has a little set-screw that stops against an anvil piece that goes through a hole in the switch... I even rigged mine with a lost anvil in Norway a couple years ago...

Don't forget you have another switch at the rear brake pedal... it'll cause the same kinds of grief that the front switch will... (haven't needed to mess with mine, so can't offer any advice)

Al...

 

[pablo666]

Check you haven't wired it up wrong, so that the switch isn't doing anything? Or a short across the micro-switch terminal?

 

[kevmeister]

I kept having these little blighters go on my 06 1200GS and eventually BMW cured the problem by replacing the brake lever itself. They reckoned the pivot was worn and that's what was causing the switch to keep failing. I've been running fine for months now so that might be worth a try.

 

[Barrmill Biker]

Bl** Electrics

Two micro switches later several hours freezing my
nuts off and the bloody back break light is still on.

Have came to the conclusion there must be a short
some where but god only knows where will have to
strip the petrol tank off and try trace the problem the
old fashion way with test meter.

Getting really peed off now missing my daily run
on the bike don't like going by car takes ages sitting
on the Kingston Bridge (M8) only up side is the
weather has been pants.

I might as well get back to the Haynes book of lies
and see if I can trace where these cables go.

All practical suggestions welcome.

 

[Clive]

Have you checked it is not caused by mud or grit on the rear brake switch?

 

[Barrmill Biker]

switch

Have replaced both front and rear break switch's
still no joy

 

[araspitfire]

If you had a meter, why didn't you just check that the switches 'switched' before buying new ones?

At least you have a couple of spares now...

The system is pretty simple... all roads lead to Rome... or in this case the ZFE..

Have a look here: http://www.r1200gs.info/R1200GS-WD2.pdf

Al...

 

[Barrmill Biker]

Switches

Both switches where in a bad way and would have
replaced them any way to be safe

many thanks for the wiring diagram looking
forward to spending many hours probing around
in the bloody cold.

 

[thumper]

This worked as you said it would. Cheers.

 

[Nick V]

Im not sure if I'm jumping in too late here... but my understanding of current BMW brake-light circuits is that the default switch condition (i.e. not touching the levers; brakes inactive) is normally-closed - NOT normally-open.

What this means is that when the ZFE senses an open line (i.e. infinite resistance) in the relevant circuit, it activates the relevant light.
Working on the assumption that the default switch condition is normally-open - and adjusting the switch accordingly - will mean that the brake light stays on all the time.

Back in 2008, I built a K1200S streetfighter with no ZFE, and conventional Japanese switchgear.
I had to rig both brake-light switches to a default condition of normally-open for the brake light to work properly.