2001 XJR, drives great. Park the car, turn off and take the key out of the ignition, and various random lights on the dash light up, some brighter than others, high beam etc, various random warning messages show up. After a while it seems to settle down and just display the odometer, then finally turn off. Coils? Alternator? Battery?

Thanks in advance,
ZIg

Battery or wiring fault.

Will load test the battery tonight... hedging towards that.

My wild guess would be that some relay is sticking for too long before letting it go (with the turn of the key most of periphery is cut off while main computer is still monitoring for a few seconds...).

I assume you are aware of the X-300 flashing dash / ignition coil correlation and therefore the question. However, that happens when the car is running and the ignition is making high voltage pulses that are causing noise in the dash circuit.

You might have a look for the TSB recently posted by motorcarman that describes a solder migration problem in the instrument panel.

I posted that TSB for the CAN bus fault but I did not realize that the poster had a CAN bus fault that was 'self-inflicted'. The cause was an OBDII devise??

bob gauff

bob:
I am not sure... It sounded like that might have been it.