Brake lights not working

[MiniNinjaRob]

Hi All,

None of my brake lights appear to work. I checked a few things and got them to work for a couple of minutes then nothing. Changed the light failure relay (the round one) in the dash, again worked for a bit then nothing.
I'm getting a brake pedal switch as soon as I can as that seems to be the next step but is there anything else I can check in the meantime? All the bulbs work fine.

[griston64]

My brake pedal switch just needed adjusting. It had slipped back when I replaced the cover under steering wheel

[MiniNinjaRob]

Thanks, worth a look for sure! Not stuck my head under there yet....

[griston64]

I cant remember exactly what i did but i seem to remember pulling or pushing the whole switch in or out ( sorry to be so vague ) and that fixed it. Along the lines of one way they didn't work at all and they other way they stayed on all the time and somewhere in the middle they worked fine

Hope that makes some kind of sense

[MiniNinjaRob]

Right this is weird. I pulled the switch out and tested it, it works as there is continuity across the contacts when it’s not pressed in and no continuity when it is pressed in (ie brake not pressed)

What to check now? I’ve changed the fuses and the relay.

[griston64]

Try putting switch back in and moving forwards and backwards and see if you can get lights to work. An assistant or garage door reflection helps

[MiniNinjaRob]

I tried pushing switch in and out while my wife watched the lights and still didn’t work.

[griston64]

Could still be the switch as I had similar thing with reverse light switch in gearbox. Tested everything and all ok but still no reverse lights. Put a new switch in and they worked

[mocambique-amazone]

Remove the plugs at the switch, build a bridge at the sockets and you will see if there is a faulty switch or something else is wrong.....

The brake light switch is prone to fail.....

Good luck, Kay

[Laird Scooby]

What Kay said ^^^^^ - the switch may check out fine on a multimeter but that only passes a tiny current through the contacts which they may well cope with easily, even if burned/dirty.

Trying to pass 6A through it for the 3 brake light bulbs (at 14V - engine running in other words, the bulbs actually work out at 25W which is what they rate them at in the USA) will show a fault up in the switch.

Link the two contacts in the plug that goes onto the switch and see if the brake lights now work, also remove and clean the fuse for them or better still, renew it.