Yes, a ****ty little ground wire will DEFINETLY cause that. How ever much current your amp draws down the power wire, it MUST be able to get it back out through the ground wire...otherwise it will try to draw even more power. Resulting in a huge current draw that the system can't handle and ultimatly, blowing a fuse. Always try to keep your ground wire the same size as your power wire. Reality is it can be a little smaller then power wire because it's only a couple of feet long instead of 20 feet but it's a good rule of thumb, also, make sure your connection point on the body of the car is solid, no paint or **** like that. Just straight bare metal to bare metal. Might also find an increase in volume