Brake tail light stays on

[Truckie]

My buddy has a 2013 Heritage w/o ABS.  While following him today I saw that his brake light stays on. He attempted to adjust the controls and it would go off temporarily.
Any thoughts?
Thanks, truckie.

[SixShooter14]

the brake lever is probably not keeping the plunger depressed when it's released. This could be due to misalignment, or if it could use a little spacer on the plunger to ensure it's depressed.


Best test is to push the lever forward and see if the light goes out. I used a thin piece of cardboard tucked into the switch housing to make sure it depressed.

[Coyote]

The rear brake light pressure sensor is bad.

[Schex3x]

Look in the front master cylinder reservoir, it might be full of crud, not letting the piston fully return

[Hossamania]

Which control seems to be failing, front or rear?

[smoserx1]

Same thing happened to me when my bike was fairly new and it was the front.  Turned out Harley had provided a new master cylinder kit that had a slightly longer spring to increase the return force on the plunger which presses the switch that kills the light.  I bought the kit but never installed it because the issue resolved itself and never recurred (and that has been over 20 years now).  I guess a little "break in wear" (for lack of a better) term solved that.  Anyway you do need to determine which switch is causing the issue, front or rear.  One the older bikes the front switch is mechanical and the rear hydraulic.  Don't know if your buddy's is the same, but likely is.  A fluid change might help too.

[HogMike]

The rear brake light pressure sensor is bad.

Was a common issue from about 2010- 2013 IIRC
Harley had a batch of bad switches, most were replaced undated warranty.

Mine did the same and would disengage my cruise control is how I found it.

[truck]

Some switches were being affected by the exhaust heat, is this one of them?

[Coyote]

The rear brake light pressure sensor is bad.

Was a common issue from about 2010- 2013 IIRC
Harley had a batch of bad switches, most were replaced undated warranty.

Mine did the same and would disengage my cruise control is how I found it.

Yep. Just pull the wire off the switch and see if the light goes off.

[Ratfade]

I've had this happen on any number of bikes, and it's always been the same cause. The easy test is to remove the brake lever and operate that little switch(button) with your finger. If the light goes out, the problem is the tang at the end of the lever. Increase its contact area by using epoxy to add a small vacuum cap or any piece of rubber which will allow it to depress the switch (button) when the lever is fully extended.
I've never not had this work.

[Truckie]

Thank you all for your input. I will be going to his house this afternoon. At least I have some direction to go
Thanks,
Truckie

[Truckie]

My buddy was able to clean and lube the front controls and now it seems to be good now.
Thanks for all the help!