Do the brake lights come on at full brightness when the lights are switched on, or do they get brighter when you press the brake pedal?
Is the 'bulb failure' light on the dash illuminated?
vaux, October 2010
first thing to check is the bulbs,are they in the right way round,[thats assuming that the bulbs are twin filament/double contact ] the pins are offset to fit in holder the correct way.