[weesmiler]

Hi,

I have a 2005 plate Clio. I was using it this afternoon without any problem, and I went to go out this evening and it wouldn't start.

A friend gave me a jump start, and the engine started, but when we unplugged the jump leads it died again. When jump leads were on, the headlights wouldn't switch off, even though the stalk was in the off position.

So I don't know if the battery is dead, or if its something electrical draining the battery. We removed the fuses for the lights, so they went off, but the battery still died.

Need the car for work on Monday! What should I do?

 

[costeau]

With your battery being _that_ flat, I'd take a look at the alternator first.

With the engine off, and no jump start cables connected, measure the battery voltage with a multimeter set to measure DC voltage.
Then, put the test leads directly to their respective battery terminals.
The reading should be no lower than 11 volts, ideally somewhere around 12.5 to 13 volts.
Given the situation, it's likely you'll get readings below 11 volts.

Then, look at the thick wire that leads from the alternator and up to the battery. Quickly check that it's intact.
If this cable is OK, disconnect it temporarily (but do _not_ disconnect the other stuff at the positive terminal of the battery),
before again jump starting the car.

Again, use a multimeter, this time to measure the voltage output from the alternator while the engine is running.
Put the negative test lead to some chassis ground, e.g. metal goods on the engine itself, and the positive lead to the output of the alternator.
You should be getting a reading of somewhere around 13.5 to 14.5 volts.
If you get 0 volts, that means the alternator isn't charging at all.