i've an 02 astra and the brake lights(just brake lights) we not working acc?

i've an 02 astra and the brake lights(just brake lights) we not working accept for the third(LED) light at the top of boot.I traced the prblem to a splitter block located in the boot.i,'ve tried to bridge it to save costs but now the rear fogs light comes up on the dash when i brake!advice anyone?