Brake Lights Need A Firm Foot

[Kevin_T]

It appears that unless I'm stamping on the brake pedal the lights don't come on. Not a problem when I'm hoofing round the lanes when most of the time there's nothing behind me! But in town I'm a bit concerned that some daft twat will get a bit too close!
The switch for the brake lights is on the brake master/servo I think. Is this adjustable for pressure at all? Or is there something else I can adjust?

[ian]

Hi Kevin, first thing I would do is to check that the wiring etc is good. Remove the two wires from the connectors of the switch, turn on the ignition, touch the two wires together, get someone to check that the brakelights come on. If they don't, wiring/bulbs are suspect. If they do, switch is suspect. I haven't heard of a brake light pressure switch which has a variable pressure control but I guess they could be out there. Dumb question, but have you got the switch in the correct threaded hole in the master cylinder?

Ian

[dave]

Hi Guys.

Ian, it is definately in the right hole............I screwed it in.

Kev, it sounds like the switch is about to bite the dust, you can get a new one from Dax or me.

[Kevin_T]

Thanks Dave, I'll call you in the next couple of days to negotiate a purchase price !

[wires]

Quite agree with previous reply from Dave that it sounds like the switch is about to bite the dust.

Don't laugh, but I have a MG (well two, actually)and I reckon that the replacement brake switches are cheap imports. They last no time at all, and give symptons just like yours - i.e. increased pressure required until they finally give up the ghost.

The best bet is to fit a relay (effectively an electrical switch that requires only low current to power the switch), and this is fairly simple. The brake switch normally has 12v +ve to one side and the wire to the brake lamp on the other (the -ve {Earth} connects to the other side of the brake lamp). The switch part of a Lucas (the Prince of Darkness) relay is between terminals 30 and 87, so just connect your existing two brake light cables to these terminals (doesn't matter which way round). The power needs to go to terminals 85 and 86 (again doesn't matter which way). Connect one, say 86, to Earth. Now test whether +ve is on terminal 30 or 87 simply by connecting one at a time with a bit of wire to the unused terminal 85 - the brake light should come on. Now T off the +ve from that terminal (30 or 87) to the brake switch, then connect a lead back from the other side of the brake switch to terminal 85. Told you it was simple.