Rear brake lever light failure

[steve68]

When I activate the front brake lever, the brake light illuminates as it should.  When I press the rear brake foot pedal, the brake light does not illuminate. 

 

I used to have hyperlites spliced into the wires in the brake light assembly but have since removed them after they stopped working.

 

I tried to clean the connector where the wire from the brake pedal connects to the harness.

 

Any other thoughts?

 

Thanks

[Michaelr11]

Check the switch by the rear brake pedal.  

[King Herald]

Probably needs a new microswitch. Mine failed and had to be replaced a couple of years ago. It was rather expensive for what it is, but it had lasted 25 years so I couldn't really complain. 

[dirtrider]

11 hours ago, steve68 said:

When I activate the front brake lever, the brake light illuminates as it should.  When I press the rear brake foot pedal, the brake light does not illuminate. 

 

I used to have hyperlites spliced into the wires in the brake light assembly but have since removed them after they stopped working.

 

I tried to clean the connector where the wire from the brake pedal connects to the harness.

 

Any other thoughts?

 

Thanks

Morning Steve

 

It does sound like the rear brake switch.  

 

The rear brake light switch on the BMW 1150 (I-ABS) is an outlier, unlike most brake light switches it is normally closed then goes OPEN at brake lever apply. (reverse logic)

 

Also make sure the switch reed is free to move & not bent or caked with dirt or corrosion.  

 

It might just be an adjustment as it is kind of a pain to adjust correctly (check your Private Messages on this site as I sent you some adjustment info)

[dirtrider]

1 hour ago, dirtrider said:

Morning Steve

 

It does sound like the rear brake switch.  

 

The rear brake light switch on the BMW 1150 (I-ABS) is an outlier, unlike most brake light switches it is normally closed then goes OPEN at brake lever or rear pedal apply. (reverse logic)

 

Also make sure the switch reed is free to move & not bent or caked with dirt or corrosion.  

 

It might just be an adjustment as it is kind of a pain to adjust correctly (check your Private Messages on this site as I sent you some adjustment info)

 

[steve68]

8 hours ago, King Herald said:

Probably needs a new microswitch.

Is the microswitch in the mechanism mounted on the foot plate?

 

7 hours ago, dirtrider said:

it is normally closed then goes OPEN at brake lever apply

So if I use a continuity tester, I should get continuity (testing the pins in the switch side of the connector) at rest, then no continuity at brake apply IF the switch is working?  Or more complicated than that?

[dirtrider]

1 hour ago, steve68 said:

Is the microswitch in the mechanism mounted on the foot plate?

 

So if I use a continuity tester, I should get continuity (testing the pins in the switch side of the connector) at rest, then no continuity at brake apply IF the switch is working?  Or more complicated than that?

Afternoon Steve

 

Look at that info I sent you by PM, it shows how the switch is mounted on the inside of the R/H side plate.

 

The switch should show continuity with the foot pedal at rest then go OPEN when you depress the foot pedal.

[Miguel!]

On 6/5/2023 at 11:49 AM, dirtrider said:

The switch should show continuity with the foot pedal at rest then go OPEN when you depress the foot pedal.

dr, Is that rear brake-light-switch logic the same for the R1100RT? TIA. Miguel

[dirtrider]

9 hours ago, Miguel! said:

dr, Is that rear brake-light-switch logic the same for the R1100RT? TIA. Miguel

Morning   Miguel!

 

No, the 1100 uses conventional brake light logic, switch normally open then goes closed at brake apply. 

 

The 1100RT  has a standard stand-alone brake light circuit, the 1150 (I-ABS) brake lights are controlled by the ABS module.  

[steve68]

So I ended up finding a used switch off Ebay ($ 35   ), replaced it and it works perfectly on the bike. Oddly, I could not get the continuity to work with the switch either open or closed.

[dirtrider]

5 minutes ago, steve68 said:

So I ended up finding a used switch off Ebay ($ 35   ), replaced it and it works perfectly on the bike. Oddly, I could not get the continuity to work with the switch either open or closed.

Evening steve68

 

If the switch is working then you either had a bad meter hookup or your meter was not set correctly.