no start

i have a 1990 honda civic hatchback 4MT. have had starting problems for over a year now. would take the car on a lot of short runs (less than 5 minutes) and it started having trouble when it would sit in the sun for awhile. eventually it always started though. left it sitting for a week once and had to push start it. after that it ran well for several months, took it mostly on long runs. left it sitting again for a week and it hasn't started since.

i replaced the battery, main relay, sparkplugs, starter, and ignition switch. i also found the IG fuse blown and replaced that too. i'm pretty sure its a problem with the ignition system wiring. but i wondered if it could be anything else.

when i try to start nothing goes. i know the starter works because i jumped it from the battery. i traced the starter wire to a relay with this yellow plastic covering and i tested it there and got nothing. does this mean my wiring problem is between that relay and the starter?