r1100rt no rear brake light from the rear brake pedal

[fizzer]

any help please ,i have traced the brake light switch wire back to the two pin connector under the front seat,then bridged the wires across and still no brake light ,so its not the switch ,should i just run a live wire to the switch ,there is a yellow and a green ,which one would i attach a live to .
i may add this bike did have an alarm on it at sometime and was taken off,so i really dont know what has been butchered .
i may add the brake light works fine from the front lever
many thanks

 

[Ian J Hartley]

any help please ,i have traced the brake light switch wire back to the two pin connector under the front seat,then bridged the wires across and still no brake light ,so its not the switch ,should i just run a live wire to the switch ,there is a yellow and a green ,which one would i attach a live to .
i may add this bike did have an alarm on it at sometime and was taken off,so i really dont know what has been butchered .
i may add the brake light works fine from the front lever
many thanks

The switch switches live too the brake light, so it’s green 12v pos (Probably green/black) into the switch and yellow switched 12v pos (probably grey/yellow) out to the brake light.

 

[fizzer]

The switch switches live too the brake light, so it’s green 12v pos (Probably green/black) into the switch and yellow switched 12v pos (probably grey/yellow) out to the brake light.

ok thanks ian,so i run a permanent live to the green ,and a live only when the ignition is on to the yellow,is that correct
thanks again

 

[Ian J Hartley]

ok thanks ian,so i run a permanent live to the green ,and a live only when the ignition is on to the yellow,is that correct
thanks again

I’m not sure I understand what it is you are trying to do.

The front brake switch and the rear brake switches are connected in parallel. So either will operate the light. You have already confirmed that the front brake switch is working.
When you have ignition on. You should have +12 volts on the green/black wire. This is then passed through the switch to the light via the grey/yellow wire. You’ve chased the rear brake switch up to the connector under the front seat. So check there for the voltage. My guess is that you will have +12volts on the green/ black wire, but nothing on the grey/yellow wire even when you operate the front brake switch. If this is the case, then it points to a broken wire possibly at the brake light unit.

I’m guessing that if you dismantle the rear brake light unit you might find a broken wire, and or corrosion.

 

[DrFarkoff]

ok thanks ian,so i run a permanent live to the green ,and a live only when the ignition is on to the yellow,is that correct
thanks again

Do you have a power source at the twin connector ON the bike side of the loom??

If yes its likely you have a defective switch you can test this by bridging the loom connector with a paperclip or split pin with Ignition on

and if you have a power probe you should be able to light the lamp down the wire when you feed positive

The Green Black is a common ignition switched positive in the bike

If it is working off the front brake switch then there is power in the wire Check the arm that activates when the brake is pushed is where it should be and not jammed up stopping it working correctly and that your have an open circuit when the brake lever up at rest and a closed circuit when you press the pedal Use a bulb and battery because an LED in a tester will light with minimal current whereas a bulb will show up a high resistance


So in summary the same two wires run the length of the bike and the brake switches form a bridge to complete the circuit when they are activated