My daughters 88 honda civic will not start - tried to check ecm (ecu) but that no longer works - I cannot find a master relay under dash? It's a sedan LX. Should I start by replacing ecm or elsewhere?

. Test all under-dash and under-hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post252145

. Perform tests in Sections A and B below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563.html