After a period of non-use, the car does not start. Upon recharging battery, no difference. In fact, it's totally dead -- no light, boot does not open. Upon turning the key, dial indicators (speed, rpm, etc.) swing to the right before coming to a halt. Where to start?

 

What is the voltage of battery? Key off positive to negative. I would start there.

 

Welcome to the forum.

How long had the car been sitting unused? Even after recharging it, the battery may be toast. Don't just rush out and by a new one, but test it as follows:

Charge the battery again. Disconnect the charger. Measure the voltage directly on the battery posts. You should see at least 12.6v, which is a very high minimum, much more than most vehicles. Next, have a helper turn on the headlights or turn the key to start.

I suspect you will see the voltage drop precipitously under load. If so, that battery is now an unwieldy paperweight and no amount of charging will bring it back to life.

 

Is there a fuse that controls all battery output? I charged the battery but no life at all, not even lights.

 

Yes, but it is not likely to have failed. Wiring diagrams at the top of this page if you want to start digging:

JagRepair.com - Jaguar Repair Information Resource

Meanwhile, have you measured the voltage at the battery? Even if the battery seems to take a charge, you are VERY likely to see voltage drop off dramatically under load. Nearly every circuit on the car is computer controlled. Below a certain voltage, the control modules simply shut down and everything goes dead.

 

Thanks for your help. Voltage down to 2.4V. Battery is less than 2 years old, so there is probably a slow leak.

 

How long was your "period of non-use" ?

2.4 volts is basically "dead" and the battery may not take a charge at this juncture.

 

Bob's your uncle.

 

Yes, dead. I got a replacement under the warranty. Everything's working!