Help please, A8 Dead

[A8XYR]

Hello,

Let the wife drive the car, next morning wont start as she left lights on :mad:

Boot would not open

My brother tried to Jump start using the red leads in the footwell behind the wood on the passenger side claiming it would work, we got power briefly as the alarm started going off and i was able to open the boot but the car would not turn over at all.

With the boot now open we tried to jump start from the battery, nothing no turnover, changed batteries nothing again no turn over.

Have we immobilised the car? as it seems that it has just shut down completely.

Has anyone had a problem like this? I have searched everywhere on here and all I can find is the problem of the immobiliser cutting the engine after starting, my a8 does not even start, or have any lights on it just appears completely dead.

Any help is much appreciated+++

[PsYcHe]

Eek!!

OK.. does anything click when you turn the key?

Check all the fuses in the passenger footwell and above the battery (most likely) to see if you've blown something with the jumpstart.

[A8XYR]

nothing clicks when the key is turned. I have checked the fuses...

spoke to someone who knows audis, they say the engine loom could of got burnt out when my brother was trying to jump it from, the red cables under the wood in the pass foot well, if it is he's written it off!

Are there jump points under the bonnet somewhere?

[IT_S8]

You havent said what car it is, but judging by the wooden plate, we'll go for a D2 chassis....

There are a number of terminals in the passenger footwell, one of which has blatently got a big fat positive cable connected to it. Attempting to jump off this isnt likely to cause the sort of burning out that you fear IMO unless you were really giving it some cranking.

There are two red wires that leave the battery via a 200amp fuse, the thicker of the two connects directly to the starter/alternator and the smaller of the two connects directly to that distribution box.

The starter itself connects behind the front drivers wheel to a junction box where the main thick power line protrudes from the chassis. Its behind a plastic cover, which is held on by 2 or 3 nylon nuts once you've removed the wheel.

The earth for starter also connects right next to it. If either of those are bad, it could explain your problems. Note also, that the alternator shares the same wiring, so if its dodgy, the battery may not have been charging correctly, which might help explain why it went so flat - leaving side lights on overnight shouldnt kill it flat really....

Also, there is a starter inhibitor relay in the passenger footwell fuse box, this controls whether or not the starter should activate, based on the position of the gear lever, eg will only start in neutral and park - It may have been knocked?

Finally, the immobiliser on the D2 is a retrospective thing, so even if you have completely the wrong key, and manage to get it in the lock and turn, the engine will still crank and fire, but will shut down about 1 second later when it figures out its not authorised, so you're not looking at a complicated immobiliser problem if that helps....

For future reference though, jumping power onto the passenger footwell power rails is a great way to get the boot open, so you can then charge it up properly direct on the battery, starting it from the footwell isnt something that isnt recommended because its the current capacity cable, and practically speaking, its very hard to get a decent electrical connection onto the terminal studs with crocodiles....