v8 Vantage - Totally dead

[BMWBen]

I came back from a three week holiday and tried to unlock my vantage... completely dead... Guess I should have hit the battery switch in the boot!

I've tried to jump start it, but even after connecting it up for a good 15 minutes with the donor engine running, there seems to be no power to anything. If you turn the ignition nothing happens at all.

It doesn't appear that mine has a battery reset switch according to the manual, and I've checked across the jump start leads under the bonnet with my multimeter and there's definitely voltage there so the connections are good.

Anyone have any ideas?

[NickXX]

I had something similar recently- had to get the AA out with a big booster pack to start it. Alternatively, if you have access to power, you should be able to juice it up quite quickly with a battery charger.

[bogie]

Hook the battery up to a charger for an hour or two, sounds like its really flat and 15 mins off another car isnt going to be enough to get it going

[V12VMan]

Have you had a look around the base of the rear rear panel behind the drivers side - that's where the battery reset button is hidden in a whole if my memory serves me correctly?

[Impasse]

I'd be tempted to bite the bullet and install a new battery. They don't particularly like going completely flat and may start to demonstrate annoying foibles in the near future even if you do manage to revive it with a jump pack or charger.

[RobDown]

When my db9 went completely flat I had to trickle charge it for a few hours before it would jump start. Turned out the battery was down a couple of failed cells, so ended up replacing the battery in the end

[arp489j]

Have you connected the positive jump lead to the + terminal under the bonnet? That won't work if the battery is dead. Instead connect it directly to the battery post. Then do the same for negative. That should work.

[BMWBen]

arp489j said:

Have you connected the positive jump lead to the + terminal under the bonnet? That won't work if the battery is dead. Instead connect it directly to the battery post. Then do the same for negative. That should work.

Yes, I was using the bonnet terminals - not sure how I'm going to get leads to the battery based on where the car currently is but guess it's worth a shot!

[BMWBen]

V12VMan said:

Have you had a look around the base of the rear rear panel behind the drivers side - that's where the battery reset button is hidden in a whole if my memory serves me correctly?

According to my manual I don't have that - if you've triggered low power mode then it un-triggers when you insert the key. Apparently.

[johnnyBv8]

Possibly an obvious question, and I know you mentioned using the multimeter, but are you 100% sure you're getting a good connection - do the interior lights come on when you've got the leads connected and key in ignition?

Edited by johnnyBv8 on Monday 5th September 11:20

[johnnyBv8]

P.s. It may be different depending on year, but I definitely started my 2006 car from the positive under the bonnet and a good earth under the bonnet. It wasn't that easy to get a good connection with the jump leads, but once I did the interior lights and dash lit up, I pressed the button behind the seat that you don't have, and it begrudgingly started!

[wafu1983]

Before you dismantle anything, clean both the positive terminal under the bonnet and whichever earth location you're using with some wet and dry to ensure you're getting a proper connection. I had exactly the same thing the other day and just couldn't work out why I wasn't getting 14.4V across the Aston terminals when I was on my source car. 30 seconds of contact cleaning and I had my solution...

I used the bare metal post immediately next to the positive terminal as my earth and it worked fine.

[66MK]

Not quite the same, but my Vantage appeared totally dead as well and it turned out to be the docking station for the key which was at fault. It was intermittent so easier to diagnose but in appearance it could easily have been mistaken for a flat battery.

[BMWBen]

johnnyBv8 said:

Possibly an obvious question, and I know you mentioned using the multimeter, but are you 100% sure you're getting a good connection - do the interior lights come on when you've got the leads connected and key in ignition?

Edited by johnnyBv8 on Monday 5th September 11:20

You nailed it! I wasn't getting a good earth connection, not in the aston but in the donor vehicle. My multimeter skills aren't quite up to scratch it appears - I misread the scale/readout and so it was telling me I had a little bit of voltage from the aston battery when I tested across the jump leads not that I had a big pile of voltage attached from the donor. Once that was rectified I found that the part of the engine block I was using as the earth in the donor isn't actually earthed, so there wasn't a complete circuit.

Attached the negative lead somewhere else, got a voltage, alarm went off, happy days! I was having nightmares about getting it recovered and days of electrical troubleshooting, so thank god.


Many thanks for all the helpful contributions above!