I just finished swapping in a ls, I did a tuck, shave and painted the bay. Before I had the engine in I decided to test my headlights and when I did I turned the ignition on then turned the lights on and they went on for a second but then everything shut off. Now I cannot get anything to turn on, no dash lights, no hazards. I tested battery its brand new and good, grounds seam good and all my hood fuses are good. Anybody have any idea a relay or fuse that could be bad. My cabin fuse panel is getting power and all fuses seam good.

 

Car?

Test the battery ground with a multimeter.

All hood fuses have voltage on both tabs/bolts?

 

The car is a eg coupe and all the fuses have power on both ends and the ground is fine.

 

What test told you this^