Starter motor and flat battery

[MarkRae]

This morning when I tried to get into my car (2005 MG ZS) the battery was completely flat to the extent that the key fob wouldn't even open the door! Luckily, I have HomeStart with my insurance, and the emergency man came out in almost no time at all. He attached his portable charger and, of course, the car started straight away.

So I drove it to the local MG Rover dealer, where they were adamant that the battery was fine and the problem was with the starter motor. Does this sound plausible? Would a dodgy starter motor completely drain a battery? I'm by no means a mechanic but, to my mind, this sounds a bit funny. Of course, if the starter motor was faulty, I guess the car wouldn't start, but surely at least some of the other systems (door lock, wipers etc) would have worked, no? Am I way off the mark here...?

[MarkRae]

> did you leave the radio or an interior light on last night

No.


> f not it could well be the alternator draining the battery,but then the chaps at the
> MG dealer would have picked that up

They replaced the alternator a couple of months ago...


> The starter motor wouldn't have drained the battery thats for sure.

Hmm - that's what I thought. It's about a 30-minute drive to the garage, so that would have recharged the battery, right? I'm thinking that they have misdiagnosed the fault...

[Seafarer1966]

MG Rover dealer....do they still exist? Rovers are notorious for the engine management system sucking up a fair amount of power if the car is left standing for a while. The clock, EMU etc. all need power whilst the engine is off.

Tip for you. Aldi are selling portable jump starters at thirty quid a piece this week. Bargain.