Dubious starter motor problem

Check all the battery and starter connections and engine earth straps. Take them off, clean them, and try it again.

I thought though that if the headlights go dim when you try and start the car that it means that the motor is drawing current but not doing anything useful with it, hence it's the motor and not the wiring?

Cheers,

Peter.

the battery is flat

It could mean that, but a bad battery or starter connection can do the same. A connection good enough to power lights etc, but not good enough to pass the 200 plus amps that the starter requires, so it takes what there is, and the lights dim. Mike.

That's my first instinct, hence I'll take my booster round with me and try and start it off that. I'm always amazed at how people give up on cars after a bit of trouble like this, it's in danger of being sold atm! When my brother's head gasket went on his 100k S-reg Escort Ford must have been laughing their heads off as he traded it for not very much against a brand new car - they must have waiting until a mechanic had a few hours to spare and fixed it for less than a fiver!

Peter.

Good one. I forgot the obvious. Mike.

Not necessarily. The starter will draw current and maybe dim the lights, but it can't draw enough to work. There's no particular rule about this. It depends on how good all the connections are. It's vital to check all connections first.

Sometimes the battery terminal will form a sort of grey skin under the connection and when you take the lead off, it looks clean but actually won't pass much current. Make it shiny (and don't forget the inside of the lead connector) and this might cure the problem.

Rob Graham

OK. I'll definitely do that then.

Yes, I saw that on a new battery I'd ordered for my car. Cleaned the posts with emery paper before putting it in.

Thanks,

Peter.

No. The battery is dead.

Steve

Yes, a good theory which fits the facts I know about is that the alternator broke, the battery was allowed to go far too flat and destroyed itself and then the garage ripped them off by claiming it was the starter motor. If that's the case is it time to sue? :)

Peter.

how do they work that out ? if the part is faulty and its within the guarantee period they should replace it FOC & not charge the customer for the labour again, if the job involves a lot of labour the garage would claim the labour back from their suppliers for supplying a faulty unit, not ask the customer to pay again !!

Absolutely. If it turns out to be the battery then either they're incompentant or rip off merchants as well.

Peter.

As far as I remember the Corsa alternators are rubber mounted. If so there should be a short earth lead from the engine to the alternator. Make sure it was fitted after the alternator was changed

John

If it's duff connections, the same applies. The starter circuit is simple: if the battery and motor and all the cables are OK, it should crank over at least.

I tried this at the weekend but it was dark by the time I got round so didn't try and disassemble anything. The battery was showing 11.9V which strikes me as a bit low for a resting voltage.

Engine started fine on the booster battery so it's not the starter motor and the garage appears to have misdiagnosed the fault! I probably should have tried to start it without the booster first but there you go. After disconnecting the booster it started fine about 5 times.

Had a brief moment of panic when I noticed that I'd connected the positive lead from the booster to the battery terminal which was connected to the black lead from the car. Is it just me or does red mean positive and black negative? The red lead from the car was connected to the negative terminal!!! Great design :) Another point of great design is that it appears as though I'd have to get the grill at the bottom of the windshield off to change the battery and possibly to get the earth strap off too :(

Peter.