JB power fuse?

We narrowed down that the JB power fuse was draining the battery, however we have a short or something else going on. For example sometimes while trying to start it will turn over and then just nothing and then more nothing. No door dinging no interior lights etc, and then sometimes while driving the gauges will flick back and forth fast and the radio will shut off and on. I just need tip or information on how to track this short or wire problem. I do not know where to begin and I cannot afford a mechanic and help would be greatly appreciated.