2004 Honda Civic Question: headlights and dash dial lights have a very slight flicker

have the alternator voltage checked while this is happening

Roy

Normal on a lot of them because they have what they call an ELD (electronic load detector) in the fuse box. As stated to be safe , have the alternator tested. Alternator output and function/command can also be monitored using the right scan tool, that way you'll also know if the controls (PCM regulated) are working.