I turned the ign on and all the electrical went out
Check the battery terminals and cable ends, they should be shiny clean, none of that black corrosion, check the battery cables for any puffy look around the ends, there could be internal corrosion, test all of the main fuses, the best way to check them is to pull them out one at a time and run an ohms test on each one. Of course it is possible that the battery could be totally shot, unable to carry any type of load.
T.S. Has once again given excellent advice. There's no question that your battery cables are the problem.
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