I've got an 04 DX civic with 95k. At random the head lights and instrument control lights start flickering or pulsating. Sometimes while this is happening my needle in my speedo will drop down and then back up fast. While this was going on I've turned on all my accessories (ac, wipers, turned up stock radio, rear defroster) to see if it got any worse but nothing changed. It then stops at random and everything seems fine.

I just got back from a long 7 hour drive this weekend and this happened 4 separate times during my travel. The problem has been going on for a few months but it seems to be more frequent. I can't reduplicate the problem it just happens.

I've got the alternator and battery checked twice and everything seems good. I check my grounds and fuses which they all check out.

Does anyone have any ideas?

 

Check for CELs, you could have a bad ELD (P1298). Or the Mutiplex Control Unit may be going bad. That's all I can think of right now.

 

I'd recommend checking the alternator, but you already have. I had a similar experience with the needles dropping, the car still running for a short period and then finally shutting off; turns out my alternator was done. Before it's demise, I noticed flickering as well.