Scratchy head time!
When my lights are off the brake lights work fine. When I turn the lights on, the rear brake light on the passenger side is permanently on - any suggestions please, MOT on the horizon.
Thanks!

 

Check you have the correct bulbs fitted.

 

Odd electrical issues like this are often caused by a bad earth, the tail lights may be earthing through the stop light bulb. Used to be very common on older cars, sadly things are not often so simple these days but I'd start by checking the earth connections to the tail lights.

 

Cheers John, worth a check.

 

I will check it, appreciate the response