S130 windows and brake light problem

[checkrail]

Hi all, My brake lights started being unpredictable sometimes sticking on, so changed the switch and then found out the fuse had blown. I have the 3 fuse boxes under the bonnet and the wireing diagram shows the brake light switch is on the same circuit as the windows which work fine.
The problem I have now is if I replace the fuse it blows immediately if the brake light wires have power to them, but if they are left off the windows are back to normal. I have tried two different switches but no difference, as it's only a plastic switch that can't make a diffence
There's something very odd going on, I would really like some ideas

Thanks very much John

[gherlt]

I have no idea about +2 or S130, but I assume you have a hydraulic brake light switch, not switch located at the pedal ?
So when you apply the brakes, there is a short in the circuit to the brake lights.
This could be at the switch itself where the outgoing wire could be touching something that comes into contact with negative ground? Did you change anything at the lights ?

[George S L]

Hi John check the wiring from the brake light switch to the lights and the lights themselves

[mbell]

The wiring at the switch is one constant supply and output to lights. So should be able to check for short to ground in brake circuit by testing for continuity between ground and the output wire at the switch.

[checkrail]

No the switch is screwed into the pedal box, basic classic Mini one

[checkrail]

I bypassed the fuse box and ran a wire directly to the brake light switch, turned the ignition on and I smelt the switch getting hot so pulled the wire sharpish.
The windows are working fine with the fuse in place

John

[mbell]

I bypassed the fuse box and ran a wire directly to the brake light switch, turned the ignition on and I smelt the switch getting hot so pulled the wire sharpish.

You've likely got a short in the brake wiring, running it without a fuse is last thing you should do. You need to start working you way through the wiring to find the short. Seem like it is between the switch and the brake lights.

[Sadbrewer]

I bypassed the fuse box and ran a wire directly to the brake light switch, turned the ignition on and I smelt the switch getting hot so pulled the wire sharpish.
The windows are working fine with the fuse in place

John

Don't mess about unless you are absolutely certain you know what you are doing. Don't risk the car catching fire...get a proper auto electrician to have a look.

[checkrail]

It's all sorted now with the existing wires and fuse box ind new switch, it's very fiddly to get the switch screwed in by the right amount

John