Rear light issues; brake lights stuck on when electrics turned on

[Iguana]

I know there are a ton of brake light questions on here, but I've not been able to get to the bottom of this one.

I recently changed the rear offside light cluster - just switched out the bulb holder and light cover.

Since then I've been having trouble with the rear lights.

If the key's not in the ignition and I switch on the lights, the rear lights come on fine.

But as soon as I switch on the electrics, the top and offside brake lights come on. But not the nearside one.

I'm sure all the bulbs are in the right places. I've had my head in the driver's footwell looking for a brake switch and I can't even see one. I'm a bit lost here, so it would be great to get some step-by-step n00b advice.

Oh, and the car is a 2000 reg Forte 1.0.

[stevo67]

Try a new brake light switch(located above the brake pedal)

[Manu]

as above, had that once

[bender]

Doesn't sound like a brake pedal switch, sounds like the new cluster you put on the car is back feeding the brake lights. Does the nearside brake light work as normal? If so try plugging the clusters in opposite sides, if the fault swaps to the nearside brake light then it's a faulty cluster

[Furioman]

the brake lights use dual filament bulbs if you put single filament ones in it bridges the circuits

[chinkostu]

the brake lights use dual filament bulbs if you put single filament ones in it bridges the circuits

or put them in the wrong way. quite easy to do