Ok, so I've been having this minor problem. The car has aftermarket bulbs but sometimes the passenger light turns off. It turns back on when I switch it off then on. It does flicker as well only when I turn them on when they are cold, but never flickers after. What could it be?

The bulb?
The ballast?
Lose connection somewhere?

I bought the car with these bulbs. I don't know exactly how old they are.

 

That happened to me in my jeep and eventually went out completely. Ended up just being the bulb.

Unfortunately its hard to tell since the ballast itself could be effecting the bulb itself.

 

Dealt with this issue for almost 2 years.exactly as you describe. Changing the bulb fixed it for a month then it started again. In my case it was the ballast.

 

Chances are it's the bulb.

Had a similar issue when I had 6K bulbs. My passenger side bulb would not light up. Flickered and all that. Also started to omit a green light.

Replaced it with a new better brand bulb and that fixed the problem.

 

Now both lights time to time go off but not at the same time.

 

I cleaned the battery connectors, since they were really corroded. I bought brand new oem ballasts, igniters and bulbs. Anyone have any thoughts?

 

I still didn't receive them. But could it have been the battery? The positive connector was badly corroded. I took it off and threw in hot water with baking soda. Now it's shining like new.