Were can I get a wiring diaframn for a 1990 Honda Civic ?
I am having eletrical problem's , with fuel .
Were is the main relay,and the fuel relay, located on this car ?

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

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

Test all fuses carefully and thoroughly, in order to not waste time and money. Pay particular attention to the ACG (S) (ALT) fuse, which is likely Fuse No. 12.

. The main relay (fuel relay) is located just above the under-dash fuse box. I have never seen a bad Honda fuel pump, even though many frequently replace them. Most fuel pump-related problems are due to blown fuses or ECM failure.

Therefore, if the problem persists, read Sections A and B below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563.html#post219438