97 Chev Cavalier No dash lights

I just installed a JVC into one of these cars. I had to take the top of the dash out to expose the screws that held the plastic cover that goes across the gauges and ac control. Now the customer is telling me her dash lights aren't working. I've pulled the radio out and checked the Illum wire from the wire harness that I installed and I put a crimp cap on it to keep it from grounding out. I then tested the Illum wire to see if it was getting juice. And my 12V tester is saying that I'm getting juice there. Has anyone ever had this problem and could I have blown all her dash light bulbs out? I've done more installs then I can shake a stick at so I'm no newbie at this. I also replaced her 10amp fuse that feeds her Mem wire to her radio which is working fine. But she has called me and told me that her dash lights are out and so is her Cig plug? I know that ford radios have a reverse neg ground that controls the dash lights but this is the 1st on any GM cars? Any help would be most appreciated. thanks ant

um check the fuse for the radio, make sure thats good, cig lighter is on  the same fuse, another cause of no dash and radio lights would be the dimmer switch u had to disconnect to remove the trim around the steering wheel, if those wires aren't plug in, u will have no dash lights or anything

I didn't even think of the switch being unplugged. I'll check that out. thanks ant