Hi there,

I came back to the car today after less than 24Hrs to find that the battery had died. Had to unlock the car with the key instead of the remote as usual. There was no electical activity what so ever.

I assumed that I must have left something on over night. The AA man got the battery charged up again and the car started. He also did a few checks and said that it was all fine and that nothing was draining the battery. However, I've been back at home now for 8 hours after driving 40 miles. The alarm has just started to go off. At first I didn't think it was my car because the lights weren't flashing, eventually I went out to check and the battery had gone flat again. The alarm wouldn't stop sounding even once I had unlocked the car and put the key in the ignition, eventualy I just disconected the earth from the Battery to shut the alarm up.

Any ideas what the problem could be:confused:

If your lucky, just a duff battery. Charge the battery and check the no load drain by connecting an ammeter on 10 AMP range. The ammeter MUST go in series with the battery feed NOT across the battery. So you leave one terminal disconnected and connect the ammeter between battery and disconnected lead.

Your looking for about 200 milliamps drain maximum. Any higher and something in the car will be draining the battery. To isolate a drain source, you simply pull fuses one by one until the offending circuit is found.

If your unlucky it could be water in the wiring loom.

Bon Chance.

The alarm should sound if the main battery voltage drops. Basically the alarm thinks someone is tampering with your car so the alarm sounds using its own internal backup battery.

If there is no current drain according the AA man, then I suspect a new battery maybe in order.

i agree battery the most likely suspect, the newer lead/calcium batteries tend to be ok one minute then totally dead the next when they go faulty

unlike the older type batteries where you would slowly lose the charge over days/weeks

Hi there,

I came back to the car today after less than 24Hrs to find that the battery had died. Had to unlock the car with the key instead of the remote as usual. There was no electical activity what so ever.

I assumed that I must have left something on over night. The AA man got the battery charged up again and the car started. He also did a few checks and said that it was all fine and that nothing was draining the battery. However, I've been back at home now for 8 hours after driving 40 miles. The alarm has just started to go off. At first I didn't think it was my car because the lights weren't flashing, eventually I went out to check and the battery had gone flat again. The alarm wouldn't stop sounding even once I had unlocked the car and put the key in the ignition, eventualy I just disconected the earth from the Battery to shut the alarm up.

Any ideas what the problem could be:confused:

Hi Muddy

All other posts noted and could be the battery, but you do need to do some other checks:

as said check if there is any current draw (test as has been said)

but a run of 40 miles will not charge a battery fully, you need to give it a proper charge for 24 hrs at about 10(ish) amps and also check the output

of the alternator, ie put a volt meter across the battery when the engine is running poss with all the lights on, you need at least 13.5 volts !

Radiotwo

Cheers Radiotwo,

Thanks for the advice, I have checked the voltage across the battery and got 13.6 volts and 13 volts with all the lights on.

I haven't been able to test for a current drain because the cooling fan wont swich off! Its been running for an hour, could this be what is draining my battery? I'm not sure how long it should run for but the dash engine temp. gauge is showing the engine to be cool and the fan is still running. I wonder if this is indicating a faulty cooling fan control unit?

Any thoughts?

If the engine is cold, and the ignition off, then the fan should also be off. The only time the fan will run with the engine started and cold is if you have Aircon and its switched on. The fan may run for a short period of time after switching the engine off, but usually only when at normal operating temperature.

Thanks Manny,

Sounds like I have found my problem. I can stop the fan from continuing to running and draining the battery when I leave the car by disconecting the negative terminal, untill I can get it to a dealer.

Cheers.

Yeah the current that fan takes is fairly substantial - deffo the problem then. Hopefully a fairly cheap thermoswitch

Cheep!

Just been quoted £158 for fitting a new one at the local dealer.

Anyone got any ideas where I can get one cheeper?

HOW MUCH :eek: