Check both sides of fule holes with the red probe and black on the earth say a bolt or somthing on the dc volt setting
Just had another look, the brake light now works when the pedal is pressed, but the front and rear light does not come on when the lights are on. Checked power across the terminal like you said to do, there wasnt any. Checked other terminals to check isnt my old multi meter or something but its fine.
could it be the light stalk or still a dodgy earth or something?