I have a '95 Dodge 3500 diesel that is now a 3 ton paperweight. The batteries are fine at 12.60 Volts but there is no electrical system in the vehicle which works including brake lights, headlights, interior lights, ignition, etc. Please help me out with some detailed advice on how to fix the problem. Thanks!!

 

Check the main fuses under the hood in the power distribution block with a DVOM.