How can I fix my N reg Ford Fiesta Frascati?

your bulb is either in wrong in the socket, or is the wrong bulb.. when you apply your brakes, the power to the light is being transferred to the headlight system ( the other terminal in the lights) check the holder etc, and the connector on the back of the cluster.. its wise to remove the other side which you didnt replace and use it for reference.. hope this helps!

Tom Yates
May 2008

sounds like you have put a wrong bulb in.check the contacts you should have fitted a double contact-twin filament-5/21w bulb which as mentioned previous has offset pins which should only fit one way,check after fitting that tail light is same intensity both sides and that they both brighten when brake pressed [dont get bulb confused with a 4/21w which also has offset pins but are not opposite each other!]

k
May 2008

check the bulb you put in is not the wrong way round,you will see 2 pins on the buld one is higher than the other but it is still possible to put in the wrong way round and cause a short

c. collins
May 2008