The problem: Friend's DX's dashboard light is messed up. Sometimes it'll turn on, and other times it doesn't work. How do I fix that? Do I need to replace anything?

 

Define dashboard light there are many numerous lights located on a dashboard... Are you saying like a light that illuminates a button when lights are on or are we talking a light that turns on for better visibility in the cabin when it is dark???

 

Sounds like the dimmer switch is going out. Replace it.

 

sorry about that.
dashlight meaning the light that illuminated the gauges

roughly, how much would the cost be for all the parts?

 

If your bulbs are still good than go with what blue integra boy said and check your dimmer switch to see that it didnt take a crap. Just go to a junkyard around you and find a civic like yours take out the dimmer switch throw the guys a couple bucks and be on your merry little way. If replaceing that doesnt help your going to have to check wiring make sure all grounds are secure and check your illumination wire for your cluster with a voltmeter while your lights are on to make sure they are recieving power.

 

hmmm.... i had my dad check the dimmerswitch and he said it was fine and it was the wiring.
and i also think it was the wiring because when i was testing his car, i charlie-horsed the dash and the lights came on.
how do i access the wires?