Accessories come on but the car will not start. Attempting to start produces a clunk and everything shuts off.

I've tried to boost the car and still get the clunk with everything powering off when trying to start.

The battery is one year old. I had it on a charger for a few hours which showed it had fully charged. Problem remains.

I have pulled the battery, put it on a smart charger, and have just load tested it. Results show that it performs as new. The cables and connectors looks new, no corrosion or physical damage. Nothing loose, everything original.

 

How loud is the clunk? Does it sound like the starter is trying to engage?

Have you just tried pushing the brake pedal harder? Sounds odd but if the brake switch is not activated then pushing the start button just turns everything off again, and you'd be surprised how common this is.

 

Dave, I appreciate your reply. I ended up doing a "Jaguar Reboot" after reading some accounts from owners and technicians. While the battery was out I held the + and - battery cable ends together for 30s. It fired right up after reinstalling the battery. I understand this is controversial to some, and SOP for others.

Interestingly, it's running better than it ever has before. Should the car start acting up again I will report back here with any new findings. On another point, I ended up using the mechanical keyed trunk release during this process, and noticed on the back of the plastic cover there was a Volvo logo.

Cheers,
GPXFR

 

I have seen a video on YouTube about a guy from UK that performed this trick when he installed a new battery on his Jaguar XK8.