Brake light BMW R100 GS?

[BMWST?]

5w/21w has continuity from each contact to body,but also has contiinuity ACROSS contacts????....rear light works but brake light does not.Front brake used to activate brake light rear brake didnt.Now front brake doesnt.Have switch removed from bike.I cant test it very well but it seems to be open circuit at all times...should be open when when fully depressed(ie brake lever at rest ) but as soon as button is released or at least when fully out there should be continuity?

[Ixion]

Continuity across contacts is normal since both filiments have one end in common (to earth).

Normal (normal ? and BMW ? ) practice is for brake switches to make when the lever is pulled in/pushed down. ie not braking, open circuit, braking , continuity across switch contacts.

Try bridging the contacts with ignition on and bulb in holder. Light should come on

(You *HAVE* tested the bulb , preferably across a battery, and confirmed that the brake filiment does work, haven't you ?)

[BMWST?]

Continuity across contacts is normal since both filiments have one end in common (to earth).

Normal (normal ? and BMW ? ) practice is for brake switches to make when the lever is pulled in/pushed down. ie not braking, open circuit, braking , continuity across switch contacts.

Try bridging the contacts with ignition on and bulb in holder. Light should come on

(You *HAVE* tested the bulb , preferably across a battery, and confirmed that the brake filiment does work, haven't you ?)

continuity across both filaments with mulimeter

[Motu]

Don't use a multimeter - I just went down that wrong track using an LED test lamp trying to find my BMW tail light fault.A multimeter or LED will show good voltage,but won't show if the circuit will support current.A normal test lamp will draw current to show if it will provide a current as well.Don't use an ohm meter for testing circuits,it will take you down every wrong path possible.

[Voltaire]

Hmmm,( looks at BMW manual).....
Ignition on, 12 volts to one side of front switch.
brake on 12 volt to other side, if not replace switch, vw beetle one is the same on 70's ones...maybe later.
Is the rear hydraulic or rod activated?
If rod ...check rear switch as these get sticky.

[BMWST?]

front brake light switch is out,bulb lights up nicely with jumper across the pair of wires running from brake light switch connector and ign on.Cannot get continuity across brake light switch no matter how hard i try and regardless of plunger position.
I have a little test lamp.With one end connected to the +ve battery and the other applied to tail light side (or brake light side,bulb in place ign off) the indicator lamp lit up (as expected) but i also expected the bulb to light up,but it didnt.Are these lamps equuipped with a resistor or something to allow only very small currents to flow?

[BMWST?]

Hmmm,( looks at BMW manual).....
Ignition on, 12 volts to one side of front switch.
brake on 12 volt to other side, if not replace switch, vw beetle one is the same on 70's ones...maybe later.
Is the rear hydraulic or rod activated?
If rod ...check rear switch as these get sticky.

will check rear thanks!

[Waihou Thumper]

Same bike, front brake light will not work when I squeeze brake lever?
The brake light does work when using the foot brake.
Is the switch possibly faulty or knackered?
I see that I have to remove tank and undo from brake lever and unplug assembly?
Could the contacts be loose or worn/corroded?