Hi guys, I have an 05 zetec 1.6 Focus which this morning decided it didn't want to start... I turned the key and just got a single click...I tried the windows and lights etc and all seem to have enough power to work but the engine wont turn over... I have checked all fuses and they all seem to be ok but after checking them I turned the key again this time i'm getting a low whine from the engine bay and a slight electrical burning smell, this is currently where i'm at? I have read another forum post on here where the guy seemed to have pretty much the exact same issue and he replaced the battery and all is now good however he did not mention about power to electric windows or headlights etc he just said the dash lit up...just want some advice before I give Halfords any money. Many thanks in advance.