Brake lights stopped working

[greg.harvey]

Hi all,

Both my brake lights packed up yesterday. I assume (though I haven't actually checked yet if this is the case) that both bulbs *haven't* gone simultaneously and that the problem is most likely with the switch. I don't have a manual at the moment, but I've had a dig and there is what looks like a brake light switch about where I've drawn the red box on the attached photo (just out of sight, but if you're familiar with the +2S engine bay you'll know what I mean) which appears to tap in to the brake hydraulics through some sort of cover. Am I right?

My plan was to short this switch out, see if the brake lights come on and if they do, replace it. Also, what's the "proper" name for the part if I need to order a replacement?

Thanks,

G

[john.p.clegg]

Greg
Looks the same as mine,switch screws into pedal box and actuates on the end of the brake pedal,yes,just short it out and check for light...you can take these apart if you're handy-andy and fettle it...

John

[greg.harvey]

Ahhh, thanks John! That "cover" is the pedal box, eh? Figures, I s'pose, as the clutch fluid reservoir goes in to it too - as you can tell, I'm not hugely au fait with engines, but I'm getting better!

My dad reckoned the switch would work with the pressure in the hydraulics, but if I read your post right this isn't the case - it's a simple push-to-make switch (or rather, pull-to-make, considering the direction of the pedal action and the location of the switch) on the hidden end of the brake pedal? If so, I guess that makes fiddling with it much simpler - no risk of getting air in the brake fluid, etc...

Cheers,

G

[john.p.clegg]

Yep,spring loaded plunger central to switch follows top of brake pedal as it moves,making contacts......

Good luck
John

[frearther]

That's really interesting, as the brake light switch in my '65 S2 is hydraulic. Go figure!!!

[john.p.clegg]

Ah,that may be because this is a much later +2 ?

John

[handi_andi]

Before fettling or messing with the brake light switch I would head to the boot and just check you haven't pulled out the bullet connector feed as I do that regularly when putting spare wheel in and out of boot. Even more annoying if that it can look like its fully pushed in but still not contacting. So worth just a quick check with a multimeter at the rear before messing forward.
Cheers
Andy

[frearther]

Actually, it had occurred to me that the mechanical contact switch smacked of a much earlier technology

[john.p.clegg]

Yes,but which would you prefer,a brakelight that came on as soon as you touch the pedal,or,one which came on as soon as the hydraulic lines reached xxpsi,or are we splitting hairs here?

John

[handi_andi]

Well how about having both, the mechanical one to switch the lights on and the hydraulic one to switch them off when the system realises that there is no hydraulic pressure and you are not slowing down. Perhaps with the addition of a relay or two it could also turn on the flashers and start sounding the horn to warn other road users of the impending doom!
Andy
PS Yes I admit brakes are starting to get to me.

[Craig Elliott]

Incidentally, the switch seems to be the same as that used in the old mini - they're quite easy to get hold of...

C

[john.p.clegg]

Going slightly off thread a little,but are any cars fitted with "decelerometer-type" switches-not patented this idea yet-that slowly flash or dimly light the brake lights when slowing and flash fast or bright when stamping on the pedal???

John

[frearther]

John,

I think Handi_andi has the right idea - the more the merrier

Doesn't Mercedes have a system such as you describe> I think I read about it somewhere. Or perhaps it's still in the prototype stage.

[handi_andi]

My parents tell a story from the 1960s about following an American car through Norwich in the fog and the more it braked the more brake lights came on, so it has been tried but don't think it caught on probably due to complexity and being extremely annoying and distracting to follow which is why 40 years later I still hear the story about it.

If you swapped over to electric power with retard braking then the heavier the braking the more power generated and therefore the brighter the brake lights would be! Just a thought

By the way, back on topic, at least for a moment, has anyone actually known a brake switch go wrong or should we be pointing our friend in another direction like the bullet connectors or the fuse boxes etc?

Cheers

Andy

[Craig Elliott]

I've had a couple of them self-destruct - the last time it happened was on the way to have the car MOT'd. The switch simply fell apart. Fortunately there was a Rover dealer nearby and they had a replacement in stock.

C