Baterry died in 91 honda replaced it but now there's no power to car. No headlights, the dash lights don't light up when key is turned, nothing has power. The ecu doesn't even come on

The ignition switch may be bad--check for wear, pitting, or melting:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-2.html#post224652