Well been at this a week now and after much Internet searching and trying to put it right I have gave up and hope someone can help me out.
I'm not sure how long I have only had the one brake light working (3rd brake light in window) but my brother first notice it after changing my alternator.
Most common reason for this seemed to be the switch on the brake pedal so I changed that with a known good working switch off my compact, made no difference and my 3rd brake light is still going off/on threw this switch so can rule that out.
Secondly I checked bulbs although I know they were fine also cleaned all the contacts still no joy, checked all fuses still no joy.
I have just took apart all earths in the engine bay that I can find and gave the a good file down still no luck!
My sidelights, indicators and rear fog lights still continue to work, it's just these two brake lights!!!!
I'm not sure what I can try next? Really at my wits end here !