Check your connections they could be dirty if they are clean them, and that might fix the problem. If not there are an array of things that could be wrong most are simple to fix (well not easy but yeah) it could be a short, a blown fuse is unlikely but possible but then it would never work (happened to me you couldn't even tell the fuse was blown the only way I found out was with a mulitmeter). I think there has been a forum on this before and there is lots of info on the web good luck getting it fixed.

 

It might also be good to read http://z31.com/repairs/dash.shtml
its a great site for us Z31 owners and that is the link to the digital dash repair instructions. It is possible it is your power supply.

 

are just talking about the things that light up the background or the digital display as well? Mine didnt work either and it turned out to be a fuse. but a lot of things werent working, like the headlight motors, my running lights, and they were all fixed when I changed the fuse.

 

Yeah mine was the fuse I remeber it scared me because it had no visible signs it was blown and everything else checked out. But when the multimeter was put to it I found out it was just the fuse (but my entire dash was out).

 

Im not sure about the lights but the thing under your seat is the factory amp.