I bought a new stereo for my honda hook it up will not work previous stereo did work don't know if the black wire which is the ground has come alose had stereo check its good need to know where the ground wire is located in the car. or give me some kind of solution to fixing it

The vast majority of cars are Negatively ground. Meaning the negative return for your car runs through the cars frame and metal components. You probaby wont find a ground wire other than the actual negative black wire on the battery, which you will find is attached to the cars metal structure somewhere. Even if there is a ground wire from another compnent within your car to connect to within the car, you can get away without using it. Simply connect the black ground wire from your stereo to somewhere metal, ie slightly under a screw or bolt that goes into the metal subframe or engine firewall under the dash somewhere, join the wire around the screw / bolt and ensure it has good wire to metal contact, the tighten the screw/ bolt up. The subframe / firewall will act as the metal conducter to return power to the negative terminal of your battery. Make take a bit of trial and error to find a good point to join the ground wire but not too difficult to figure out.