Headlights on my 2008 G35 (150k miles) went out on me, but occasionally they would come on briefly when I started my car. Assumed the bulbs were okay, so a little forum surfing and ebay brought me here: I replaced the ballast on the driver side, and the light stays on now, but it twitches. Every half second or so there is a chirping sound and the beam jumps to the right. This happens while parked and while driving. Extremely annoying, would rather drive without lights. Haven't tried to replace the passenger side yet. What did I mess up? And how do I fix it?

 

So is it the bulb that is twitching or the AFS unit that is twitching. If it's the bulb, swap the ballasts side to side and see if the problem continues.

 

Definitely this is the AFS. I bought two now ballasts, same thing happens when I interchange them. The light stays lit, but something flicks the beam every half second or so. It doesn't start right away. When I turn the lights on initially, it is "calm" but after 1 minute or so , it starts to twitch.

Anyone know what to do?

 

Are you using OEM Ballasts and bulbs?
Did you test:
your battery?
Your alternator output voltage?
Battery cables for any corrosion?

Follow the troubleshooting steps in the FSM?

http://www.nicoclub.com/service-manu...Sedan/2008/EXL

Check IPDM
BCM
Headlamp low relay

See page EXL 68

Telcoman