Morris Minor Owners Club

hello every time i go over to my car i seem to have a flat battery i put it on charge and without startin gthe car the next day the battery is flat can anybody help me ??

Either the battery is ruined - or something is draining it. To work out which - charge the battery up and then take the earth terminal connection off. Then return next day - pop the connection back on - is the battery ok ???

battery brand new the other week so im shure its not that i took the interior light bulb out aswell to see if it was that so i m not shure what could be draining tha battery

Does it have an alternator?

no it has a dyanomo which i replaced brushes in many thanks

If the regulator is faulty - it may be jammed closed and causing the drain - so try with the dynamo disconnected..... You don't have a wireless or any other equipment like that? When you fitted the new battery - is it connected the same polarity as the old one - you haven't swapped polarity???

so what should i do just disconnect the dyanmo and see if the battery goes flat?

and yes we swapped the polaraty of the battery when putting a new 1

As before - yes - charge it up and disconnect the dynamo and leave it overnight..... But is the battery connected right way round? Ahh - I see you reversed the polarity -so did you repolarise the dynamo?????

no we just swapped it over and left it so could this be the cause

Exactly........ You must repolarise the dynamo to the new polarity. You must also swap the coil connections over - and it would be wise to clean or renew the points in the dizzy - and the points in the fuel pump. To repolarise the dynamo - disconnect the small cable -take a wire from the battery non-earth connection and 'flash' it several times on the small terminal on the dynamo. Then check inside the regulator to make sure the points are not welded closed - you may have damaged it when running it wrong polarity.

hello my dad seys its fine and should work it is charging the battery atm so were going to have a look in the regulator to check this while that is we can see if the battery is knackered but when started puts of 13.31 volts so i think the dyanmo is charging but something must be draining the battery as you say but i don tknow what it was fine all summer then winter set in and it keeps dying i havent used it much in the winter but every time i do the battery seems to be dead so cant drive it anyway thanks again

Well - as suggested earlier - take the terminal off and leave it overnight - and see if it's flat or charged next morning. It should be 13.8 to 14 volts when charging.......

green123 wrote: the battery seems to be dead so cant drive it anyway thanks again

You could always use the starting handle

turns out to be regulator at fault but still think something is draining the battery the regulator wasent charging the battery properly so i changed it with another unit also think there is something draining the battery any ideas what this could be

The regulator would be faulty because you ran it wrong polarity. Have you NOW repolarised the dynamo??? Disconnect at night to PROVE the 'discharge' theory. Nothing will discharge it unless you leave something switched on - or the Regulator fails to open.....

how do i know if the regulator opens or not can you see it ? i put a wire across is it suppose to spark or anything thanks

Yes there should be a small spark as you flash the wire across the small terminal. The bobbins in the regulator should be free - not held closed. Check with the battery disconnected because if you push them closed with battery ON - they stick on!

If you gave the full story of what you have done instead of trickling little bits of information then it might make it easier to diagnose the problem.
If you take the cover of the regulator you will be able to see the contacts opening and closing when you rev the engine. The ignition light should be on when you turn the ignition on and go out when you rev the engine
When you changed the regulator did you replace the connectors in the correct places and are the wires secure?

hello i will take a photo so i can show you im not 100% shure i will put a wire across like you tell me and see if that helps then take a picture of voltage regulator cheers anyway