Battery drain.

[E30Sport]

A problem has just arisen with my '02, A4 1.9 TDi. I left the car on the drive after it had been running perfectly and when I came to it the following morning it was dead. Got it started with jump leads and it ran fine even after turning of a couple of times. Left it over night again and the same occurred. Jump started it again and took it to have the battery and alternator tested. I've been assured that the battery is good and the alternator is showing a reading of 14.2. I have read one of the other threads which has a similar problem and says that it could be related to the radio, I will be removing the fuse tonight to see if that makes a difference, if not, any further suggestions would be greatly appreciated.
When eventually getting the car running again, the fuel gauge is showing empty, fuel warning light is on and remaining mileage is showing zero. I know that it has fuel as it was filled to the gunnels around 20 miles ago. Is there a way of resetting the fuel gauge following complete power failure? Again any suggestions would be appreciated.

[jonbaker]

That was probably my thread re the radio draining the battery. With regards to the fuel indicator, i haven't had that problem with mine when the battery died. I don't think that would be related to the battery running flat. Possibly a faulty sensor perhaps. I'm sure one of the more experienced members here would be able to advise . They are a good bunch!

[E30Sport]

Removed the radio fuse and left it overnight, when trying the following morning it was completely dead. Any ideas?

[inertia]

do you ahve any aftermarket electronics ? alarm ? amps ? sat nav ? anythign inthe ligter socket (this stays live with the ignition off).

[bora(ing) nick]

For it to drain the battery overnight, it must be a fairly sizeable load being drawn.

I'm sure i've also read somewhere that the tracker (if fitted), or alarm can be the offending item.

You could try to just lock your car on the key rather than the alarm and see if that makes any difference. (oobvously make sure that your car is secure.)

Just a few other points i've read are, Boot light stays on, glove box light stays on.

Good luck

Nick

[E30Sport]

The night before the first occurrence I had actually inadvertently left the car unlocked so I doubt that there is a problem with the alarm etc. I have not got any after market equipment fitted and I have checked that the boot light is not staying on. I have not yet checked the glove box light but I will do that next. I think I will have to admit defeat and call an auto-electrician.

[dansansome]

if you are any good with a multimeter?

you could remove individual fuses and connect the multimeter inline as an ammeter in place of the fuse to see how much current is being drawn down through each fuse when the ignition is off etc.

that should at least narrow down what circuit(s) are draining the battery. you should expect wuite a few circuits to be drawing under about 0.5A (stereo has a "memory" wire, alarm etc will all draw some current), the ones you need to persue will be the highest current drain.

[bora(ing) nick]

if you are any good with a multimeter?

you could remove individual fuses and connect the multimeter inline as an ammeter in place of the fuse to see how much current is being drawn down through each fuse when the ignition is off etc.

that should at least narrow down what circuit(s) are draining the battery. you should expect wuite a few circuits to be drawing under about 0.5A (stereo has a "memory" wire, alarm etc will all draw some current), the ones you need to persue will be the highest current drain.

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Good advice... only thing to watch out for is when you remove the fuse to the radio, you'll reset the memory .

Nick

[RobA4]

Hi, this is the exact same thing that is happening to my car (exact same model and year too!). We have tried all sorts as well.... ie. no alarm, checking all lights, not locking.... etc...

Last week we decided to take it into Audi to have a service and a thorough check on their machines... the end result - NO FAULTS FOUND! According to the garage, the car is in excellent working order!

Obviously not - battery flat again & again since! Like you, working absolutely fine one day, then the next.... flat as a pancake! Out with the jump leads and away to go again!

Any suggestions gratefully appreciated... we are as mystified as you

[zubeir]

I also had exactly the same prob on my 02 A4 a few months ago. I replaced the battery and so far have had no issues, even with the car not being driven for more than 3 days.