kept breaking down, in the end thought i had dead battery as wasnt holding charge. replaced battery and new battery was definitely taking up charge. went on hols all over scotland no probs. then started feeling sluggish yesterday. died just as i got home now wont start. is this the altenator or could i have electrical fault? the electrics are a bit dodgy (eg ariel works one day not the next, seatbelt warning light flash all the time)