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MG Midget and Sprite Technical - Starting problem - not battery

A bit of guidance please from the forum. I have a 1961 Mark 2 Sprite with pull button ignition starter. Didn't start last week so I assumed it was the battery. Charged up the battery overnight - still nothing. Attached jump leads from donor car, pulled ignition button and started straight away. Left running for about 20 minutes. Turned engine off - tried to re-start immediately but again absolutely nothing again. Is this most likely the starter motor? I am eliminating the battery and the ignition switch as the problem. If I remember correctly I replaced the starter motor around 7/8 years ago.

Thanks.

Tim, Edinburgh
TJ Prime

Just a basic point - have you removed and cleaned the battery lead connections and battery terminal posts ?
M J Chapman

Im betting its the battry

2 issues...
1. The battry can show 14 volts and still be bad, the plates inside can wear out... Take the battry to any bat shop and they can test it for free ... Takes about 2 to 20 minutes depending on state of charge

2. Actually pull the cables off the battry and look for corrosion inside the battry cables as well as on the post themselfs...white and greenish color of powber

Nope... The starter id think is fine as well as the ignition switch...imho
Prop and the Blackhole Midget

Unlikely to be the starter motor, as it starts OK with jump leads.
Dave O'Neill2

did you check electolyte (water) level on all cells before and after charging the battery off the car

as said clean battery posts and battery clamps

and clean, secure and protected connections to starter

clean, secure and protected (all) earth leads

you could check battery power with multimter if you have one

you could try connecting a jump lead from battery earth to near starter to see if it's an earth problem
Nigel Atkins

Using your jump leads, connect one lead from the battery earth terminal (+ve) direct to a good conducting point on the engine, like the alternator bracket. This will eliminate engine earth problems. Use the other lead direct from battery to starter solenoid. If it doesn't then start like this then it must be a battery problem.

PS sorry Nigel, my slow typing on a small smart phone screen!
Guy W

Guy yours is more detailed

but I did allow for a change to -ve earth :)

see I'm slowly getting better





apart from the lapses :)
Nigel Atkins

I see you cunningly avoided saying what the polarity was!
I just assumed it predates the change to neg earth.

Of course it is unlikely to have an alternator. Perhaps l should just have said generator bracket
Guy W

Fire in the hole...

TJ prime says its a... "1961 Mark 2 Sprite"....was that a positive earth car

Prop
Prop and the Blackhole Midget

Well Prop, If you look at page 95 of your well-thumbed copy of "Horler", you'll see that neg earth wasn't introduced until November 1967.
M J Chapman

Yes Prop, it definitely should be a positive earth car, which is why I described it as such in my suggestion about using a jump lead direct from the battery to engine as an earth. But as some have been converted to negative earth, Nigel carefully avoided assuming anything.

As regards starting ability, it doesn't effect anything. The starter is known to be good as it works with jumpers off a good battery. So the fault must be either the battery itself, or with the various connections in the earth or power supply circuits. Testing with jump leads as I suggested would identify where.
Guy W

Fire in the hole....again

Yeah... I just wanted to high light this little concept that it might be a pot earth... I didnt knoe for sure, and it seemed like we gracefully touched on it...and i wanted there to be more hammering on it, cause im pretty sure i wouldnt want to watch a battry detonate with a few inches of my face.

So thank you for making this a little more of a warning to our new friend

And like i said at first... I agree, bad battry as in a dead cell, or corrosion around the leads...the starter and switch are fine
Prop and the Blackhole Midget

Thanks everyone for your comments and advice. I'm off tomorrow so the battery is getting checked out with the terminals etc. I'll keep you posted. Tim
TJ Prime

saw this on Battery megastore

6. The use of petroleum jelly (Vaseline) is not necessary on modern polypropylene batteries, but there is no disadvantage in using it. Smear lightly on the terminals. It is recommended for hard-rubber batteries. Do not use grease. - http://www.batterymegastore.co.uk/page/faq/

I still think I prefer a small dab of copperease on each post between post and clamp
Nigel Atkins

This thread was discussed between 01/10/2012 and 03/10/2012

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