Aston Martin DB9 won't start after water ingress
 

I fear the soft top might be leaking but, whatever the cause, a soaked drivers well floor panel seems to have resulted in the engine failing to start. The electrical system seems fine: lights, wipers etc all work but, regrettably, the engine won't fire into life. Anyone know if there's an electrical cut-out switch I need to reset?

Many thanks

Do you have a OBD2 scanner? You can try to pull codes if you can turn the car on.

Thanks for this. Regrettably I don't have a scanner (I'll order one now!) but, the dashboard all lights up perfectly well showing the usual messages (one tire is slightly down and emission system needs service - in other words, car needs a good run out of London's 20 mph restriction zone). I was hoping I'd see a message saying 'battery low' or something similar.

It will not tell you the battery is low, V12 does not want to start if you don't have a good battery. It will crank, but not fire. If you suspect water causing damage the first step is to dry it out.

Many thanks, drying out underway. Given the battery is under the back seat behind the driver's seat - and I think the water might've seeped in that side (very damp behind the driver's seat), I imagine that there must be a cut-out switch if water shorts anything around the battery. Just can't find any mention of it in the handbook. Think it's back to the garage tomorrow: kerching! Ho hum.....

Source of db9 failing to start (with charged battery)
 

Hi, I habe had a few of these and had to fix an issue caused by water ingress. My DB9 volante would sometimes start and then just click when pressing the start button. I changed battery to no joy and stripped the interior to follow wiring (after ruling some other issues out). The culprit is the main red power cable that runs from the battery to the engine. This runs in the drivers footwell and is bolted THROUGH the floorpan into the wheel arch and up. The bolt corrodes and in my case had snapped and was shorting. I will add pics. Fix is simple, dry out by removing sponge sound proofing, filing and sanding floor pan and replacing rhe bolt connector. I used a new bolt with a series of nuts and reused the plastic grommets.

Hope this helps, a good test before taking interior out is to put a big jump pack on engine and if this starts the car it is probably the cable connector or battery terminals.
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