1998 Pontiac Sunfire dashboard lights are out

I have a 1998 sunfire. For a couple of years my abs and brake light have been on-now the dashboard lights are totally out. Not a fuse and I have tried the dimmer switch. I recently went to midas to get a muffler-the man working on it noticed my abs light was on and mentioned that he worked on sunfires and cavaliers and told me this was a wiring harness problem. Then on the way home, my dash lights were out. Coincidence? Or did he do something to my car so that I would have to call on him to repair it? I am a single woman and I know that a lot of these places will try to scam women thinking we don't know anything. What could he have done to make my dash lights go out? I can not see the speedometer! Help!