sudden flat battery

[jeff jackson]

Hi All,
Got the +2 back on the road after 18 months. All that was needed was a tyre for the MOT.
When I went to start the car, the battery was completely dead, not even an ignition light. I did charge the battery up, but it would only crank the engine over a few times. So I invested in a new battery, and engine started first turn. Great!
But to my dismay today when I went to start it, the battery was completely dead again, no ignition light - nothing.
What do the forum think is happening here? It must be a complete short to drain the battery to nothing. But where?
The car can be sat for days, and it will be fine.last time it was started was Sunday.(Five days ago).
Any ideas very welcome.

Kind regards
Jeff 72+2

[AussieJohn]

Is a light on in the boot, bonnet or interior light?

[spridget]

Jeff,
Do you have a cut off switch ?

Franck

[jeff jackson]

No lights on in the boot, I don't have the bonnet light, and no interior lights was on.
Strange thing is the car will be fine for weeks then leave it for one day, nothing!
The only thing that is powered is the radio, for the station memory, and the clock.

Jeff

[bob_rich]

hi

I am assuming things like internal lights staying on and such things have been checked and eliminated. Do You have an alternator or a dynamo? or have you fitted an alarm system?
a faulty alternator can drain a battery in a few hours and modern alarm can drain a car in about a week. Faulty regulator with dynamo's are less common to stick on. It may also be that if the car has not been used for a while the alternator/dynamo brushes are stuck so that when you use the car it drains the battery. If you have a voltmeter check that when you blip the engine that the battery voltage rise a to about 14 to 14.5V with no other load on. If you dont have a voltmeter blip the throttle from idle to a 3 to 4K revs with the headlights on they should change in brightness if the generator is charging OK

hoper this helps best of luck
Bob

[john.p.clegg]

Jeff
If none of the above apply,you're going to have to bridge the fuses with an ammeter...with all accessories off and a 10 amp meter,short out the fuses in turn (remove the fuses whilst doing so) to track down the drain....May help if you place your ammeter in series with the battery first to assess the amount of drain,,

John

[jeff jackson]

Hi All,
Thanks for all the replies. Guess this is a job for tomorrow.