cambria

I have just installed a new used central electrics panel, repaires about a dozen burned wires with butt conectors and shrink tubing in the dash board wiring harnes and have replaced the engine wiring harness. I am now looking for a way to test everything befor I power up the system. The one test that I could think of was to contect the possitive side of the battery and read the number of volts between the negitive and ground, with the key in the on position. That reading was 0. I have done a search but haven't found anything that is applicable. Any help would be appreciated.
Thanks