I have no electricity

Make sure the battery cables are tight , then check voltages till you find the problem , you have probe of some kind because you tested the battery

What was the battery’s voltage? Dirty terminal ends? Severe voltage drop across the main power or ground cables, blown main fuse in the power distribution box.

You have what is called a short to ground. A wire that's insulation is worn away or cut and touching the frame or other metal part of the vehicle.