Plugged a trailer into the el yesterday and now the stop lights are staying on when the car is started and brake pedal isn't depressed.

When the trailer was plugged in the trailers RH indicator didn't work but then did start working?

all the car light seem to be working fine

cheers

Your switch on the pedal is faulty, replace it with a cheapy from Supercheap and it will fail again in a year or two.

Ummmmm what does brake light's working or not got to do with a 6cyl engine,
apart from the motor running the alternator to charge the battery to supply the power for them to work?