I have a 1993 Honda Civic DX. I have done K-Test, replaced main relay, checked all fuses, and rang out all associatred wires. I get 0V at fuse 18. Where does fuse 18 get its power from. My drawings are crap. Where can I get some good, complete electrical drawings?

Try cleaning the main ECM ground, located on the thermostat housing. Also, remove and clean the contacts on Fuse #18.