Car has no power. 1985 Crown Victoria
I replaced every thing possible on my car but one
day I was working on a radio installation and went
to turn the key I had no power. Took my battery to
auto zone but it was good. Now im lost to why my
car is not getting any power
Battery has a full charge and battery cables are all good. There may be fusible links, follow one of the positive battery connections to find fusible links, if you haven't already. You can use a test light to check fusible links, there should be voltage on both side of link. If fusible link stretches, that also indicates a faulty fusible link. You can also use test light to check voltage on fuse circuits in fuse box. Some fuses are hot all the time, some go hot with the key on.
check your work when you were doing the radio.