I have a 2000 XJ, that I've had for two years, with a factory cassette/CD radio and the display lights seem to come and go at will - either on or off - for days at a time. There seems to be no particular reason or influence to make them go either way.
Is there a known reason for this malady, or is it simply a glitch in the factory radio electronics?
Everything else on the entire truck seems to work, and this is the only malfunction that I've ever noticed, which leads me to believe it would be not impossible to isolate the source.
Is it a simple solution or something I need to live with?

 

Any help?

 

look for a wiring diagram (do a search). It is the orange or the orange / white wire that controls the illumination, check the connections.

 

Hi. I had this same problem with my 2000 XJ with the cassette and CD player radio.
I noticed when I took my dash apart around the radio and firmly slapped the top of the radio while the vehicle was running that the display would briefly turn on! I knew that there must be a loose connection somewhere within the radio.
I took out the two bolts that hold the radio into the dash so I could pull the radio out, take it apart, and wiggle things around while it still had power, in order to find where the loose connection was.
If you take the face of the radio off and then take the left side of the radio off, (the side with all of the heat fins,) you will find a bunch of parallel strips of metal running from a circuit board on the bottom of the radio to a circuit board on the top of the radio like in this picture I took:



When I placed some pressure upon these strips I was delighted to find that my clock turned back on until I removed pressure. To permanently fix the problem I just bent all of these strips outwards and my clock has been illuminated ever since and has not given me any trouble.

 

Thanks for your post. I've been trying to resolve that problem for a long time.
TO contribute something for the next guy....
That bunch of strips connects the two circuit boards, why they didn't use a ribbon cable who knows. It's like a 10 pin plug in connection, with the pins/sockets on what's the lower side in your picture.
Rather than relying on bending things I was able to work some Deoxit contact cleaner into the connector...seems to have fixed it.
Thanks