!991 XJS no Power at all, no light, etc.

Well........the car started up today.......I used a proper set of cables and made a good connection and it started right up. Once it started I was able to see that one of the interior light in the back was in the on position........so I feel pretty dumb, but glad.......
Thanks for the input fellas.....it's good info for the future!

Thanks for the info Doug...much appreciated.......now all I need to do is find the time to check all these items!

Right, basics first.

After checking battery voltage, and checking the battery cables at the battery itself, and the main ground point for the negative cable, I'd move to the engine bay.

On the firewall are two "+" voltage junction posts. A little hard to spot but they're there. They have black rubber boots. Look on the firewall roughly below the area of the rear of each cam cover.

Anyhow....

These "+" junction posts are fed by the battery "+" cable and, in turn, supply B+ voltage to all the various sub-systems in the car. So, check for B+ voltage at the posts and make sure the connections are clean and tight.

Cheers
DD

Thanks Josiah........I'll start by measuring the voltage at the battery and then move to the next possibilities ......

Is there any power in the battery? If you measure the voltage, you should have at least 12.5 Volts.... I suspect there is, otherwise the problem should have been solved with the jump.

If there is power in the battery, then I would start tracing for voltage at the hot side of the fuse boxes. Through this, you should be able to isolate the component or connection that has failed.

I don't think a failed ECU or other component would control everything else's power, so it should be a fuse box, cable or connector.

This is one of those things that is best solved with step by step, logical, methods.

Josh Bartlett
1997 XK-8
1969 E-Type
1937 Packard 115c