Is harness different on a 94 Camaro then 95 Camaro?

Yes, the wiring harnesses in a 1994 and 1995 Camaro are different, although the differences might not be massive. There were revisions and changes made to the electrical systems between model years, so you can't directly swap harnesses. Some components may be interchangeable, but you'll likely encounter compatibility issues if you try to use a 1994 harness in a 1995 car, or vice-versa. The connector locations, wire colors, and even some gauges might be different.