Hi 1996 Vectra 1.8 GLS. Starter motors "whirrs" without engaging for first (typically) 6 to 12 attempts to start. Then, eventually, it engages and engine starts OK. First, the diagnosis. Is there any chance this could be weak battery / poor earth / dirty connections or something similar? (BTW, dash lights barely dim when whirring, but when I recharged over Xmas, it started first time next morning...) Second, if starter motor is broken, (a) how hard is it to swap? (b) approx how much is a replacement? (c) should I go to Vauxhall shop, or can anyone suggest another supplier? (d) is motor engagment mechanism-thingy repairable? (e) how much might garage charge to do the job for me? (not too keen right now on spending hours underneath in the cold and wet !) Many thanks for any answers / help.