My grandson was putting in a new radio in his 2002 GMC 1500 truck. The dash lights, speedomete,and RPM went out. Any idea what caused this?he changed the fuses.

Sounds like you cut a ground or power wire when installing the new radio. Go back over your wiring and also look for any possible shorts from your new connections to ground or power. Also, it is possible you partially unplugged a connector while working in the area. Make sure all plugs are completely seated.

Put in the new fuse u blow up when putting in the new radio its in fuse panel

And marina is right

sounds like a main fuse or main hot lead

http://www.justanswer.com/car/0smbz-find-fuse-box-diagram-2002-gmc-sierra.html#

Changing a radio in a newer vehicle is tricky as everything runs through it. Not a job for a do it yourselfer. I was told this by a friend who's a mechanic.