11 replies to this topic

[Jammers777]

Brake light switch appears to be working in reverse, switch replaced, still the same, is there anything else further back to cause this?

[smurfomatic]

Is it the switch attached to the brake pedal? Disconnect the wires and join them together, see if the brake lights come on and off. It's a simple switch, so may just need to be adjusted.

Edited by smurfomatic, 09 April 2021 - 02:01 PM.

[KTS]

when you say 'working in reverse' do you mean the brake lights are permanently on unless the pedal is pushed down, or that they come on when reverse gear is selected ?

[Jammers777]

Sorry, yes pedal down, lights off, pedal up lights on, just the brake lights.

[Spider]

It could be a poor Earth at the Lamps.

[KTS]

I'm assuming we're talking about the later type switch that attaches to the pedal box rather than the hydraulic type

Has it been fitted the wrong way round ? It should be mounted so that brake pedal in its resting position depresses the plunger and breaks the circuit

[andyapanel]

The quality of those switches is dire. I had a new one fail after six miles recently. Eventually I built one operational switch from three carcasses.

KTS's suggestion is intriguing  :)

[beardylondon]

likewise, I had one fail after 6 months, there are some cheap copies out there.

[Tornado99]

I once had a plastic brake switch melt from powering the lamps. That was on a VW Rabbit but could also happen with the mini plastic switches.
I understand these have some adjustment threading to get them in best position to brake pedal lever. Maybe this is the issue here?

[Jammers777]

Hello, had a play around, there is a 10mm nut which releases a slide adjuster, tried that and still not reaching.

[Spherix]

If it's the right way around, then your issue lies elsewhere. The switch doesn't actually switch, it break or connect the 12v line. If your brake lights are always on without pressing the pedal at all (take the switch out entirely and leave wires connected for example), they are likely getting 12v from a fault source.

[andyapanel]

If the brake lights are getting 12v because of a bad earth in the light unit, then depressing the switch will equalise the voltage and they will go out

I think Spherix has hit the nail on the head.

Earth the rear lights and see what happens.