dash light out

it's as simple as the dash light won't turn on. it's a 92 civic ex 4dr. i checked the fuse but it was fine. when i hit the dash hard enough the light will flick on but only for a few minutes or until i use the blinker. i'm sure the bulb isn't out so there must be a connection failure. WHERE DO I START?! i bought a 'chilton' but that didn't even have a diagram on how to remove the instrament panle. i'm stumped. dimmer switch? bad fuse box? loose wire? a step-by-step would be awesome! i just really don't know to much about the electrical. thanks guys!

open or short wire. get a multimeter. get a helms to start. the diagrams are awesome.

thanks for the fast respond! i'm not sure how to check the dimmer switch so can you walk we through the removal? i'll deffinetly going to go get a multimeter but where would be the best place the test the circuit?