Ford focus Brake Light Problem, The 2 side brake lights do not work and i have changed the bulbs, the one above the rear window works, A garage has advised me could be the brake light switch, Would this not also affect the top brake light it is was the brake light switch

CHECK THE FUSES

The third or High Mounted Brake Light runs straight off the brake light switch on the brake pedal arm. You say you tested the "brake unit"? I assume you mean the third brake light assembly, and if you get power there when someone steps on the brake pedal, then the bulbs are bad.

The power flow for the brake lights goes like this: Fuse ->Brake switch -> Turn signal switch -> Rear lights. The only difference is, if you have a 3rd brake light in your rear window, that gets its power directly from the brake switch. It does not go thru the signal switch first. So, if you are having a brake light problem, and your fuses are good, check the 3rd light in the rear window, if it lights up (assuming the bulbs are good, no one ever changes them), then the problem is most likely in the turn signal switch, hope this helps!

Broken wire where trunk lid opens

If bulbs are definetly ok you can look behind trim on the left side in the boot, which covers the space between the boot floor and the window, you are looking for a green/red wire in a connector. this is the power cable which supplies both rear side mounted brake lights. You should check for voltage at this wire when pedal depressed. If no voltage you would need to trace this back to where the wire is joined in the loom as it feeds off the wire which supplies the high mounted brake light and you have stated that this works. Would still double check bulbs first though if you did'nt replace them. Hope this helps.

yes it sounds like the turn signal switch is defective, the brake lights go through that switch as well.

check the bulbs.mine were changed and some genius put wrong bulb in and i had exact same problem as you.make sure tail/brake bulb has double steel connectors.my drivers side one had bulb with single connector,i put new bulbs in both sides and problem fixed.hope this helps mate

hi, i have sorted this problem on my 99 focus ghia.,check both your tail light bulbs.someone put the wrong bulb in and i had the exact same problems you described.the bulb for brake/tail light has two steel connecters and and all other bulbs have one.i put proper bulb in and the problem disappeared.now lights working perfect and sidelights dont come on now when i brake :)change both brake/tail bulbs on each side.1 euro will fix this problem.hope this helps.

Yes first thing to do is replace the bulbs. next check the fuses as the side lights sometimes run on a different source then the side.

and lastly check all the other bulbs to make sure they work. If so then the above shoulf fix it 99% of the time, if not then you have a power/wiring issue.

hi i had problem with brake lights too.on inspecting my bulbs one of them was a single connetor bulb instead of double.changed bulbs on both sides of car and put double connect bulbs and everything works perfect.cost?$1.50.hope this is of some help,it certainly done the job for me

sounds like your fuses . you should check them