My chevelle has a small problem.The wiring is mess up.the headlights work,but the brake lights don't work when the headlights are on.The side marks are always on. the rev lights don't work at all. I talk to some on they told me it sound like a ground wire problem. Could some one give me some advice on where to start lookig to solve the problem.

Start cleaning and tightening all the grounds, checking for loose connections, I would suggest a wiring diagram, you have some other stuff going on there

Sometimes if one uses a front harness from a different year, it effects the way it connects to the bulkhead as far as routing of the wiring. I had this problem and had to trace all the wires by hand and through trial and error with a diagram to get it right.

Start with checking the bulbs, then check the fuses, then check the grounds, after that you will have to trace the wires looking for a grounded lead