You have power feeding back through the brake lights from the head lights. Follow the wires from the brake lights and make sure there are no wires that have for some reason " rubbed through " and are touching. I had this happen when I wred my car up for a trailer.

 

hello how can i find out if this is whats wrong with my focus 2009

 

Three things to check.
Brake light switch

Hazard switch

If you have a hatch, wiring

 

I am currently having the same issue, The wires in the hatch were in poor condition so I fixed those but it has not corrected the issue. I guess I will go to the hazard switch and the brake swith from here. Any other ideas ?
Also would it be beneficial to replace the wiring for the hatch ? How labor intensive would this be ?
Thanks for all of the help.

 

Have you replaced any conventional bulbs with LEDs recently?

After I put too many LED bulb replacements in my 97 cougar when I turned the lights on 3rd brake light and everything stayed on. After I switched back to filament bulb everything went back to normal.

 

No , I have only regular bulbs

 

have you changed a brake light recently ? the brake lights and tail lights are combined if the wrong bulb is fitted it shorts causing the brake lights to light up try removing each bulb separatly when the lights are on and see if the other brake light goes out.
had this fault a few times its nearly always a bulb

 

X2 - that pretty much covers it, With pictures as well!

Check it out step by step & get back to us with further questions/results...

Luck!

 

Hi wonder if anyone can help just changed my brake light bulb and now when I press brake the headlight light on the dash board comes on and when i put my headlights on the brake lights stay on would appreciate help as don't know much about it have a 2007 ford focus mk2 thanks

 

What if the entire set up is LED? i have all LED's and have the problem of constant lights to the extent that you cant tell i have applied brakes when driving. I've added load resistors, and replaced some fuses. any info helps thanks

 

Add more resistance to the normal running lights to differentiate the light output......

 

You didn't state your model, but often the wiring to the rear hatch breaks inside the rubber boot between the body and the hatch. Pull the rubber boot back and take a look at the wires.