2002 Chevrolet Cavalier drivers side Headlamp problem

I thought I had a bad bulb.
I finally was able to separate the side marker from the main assembly.
but to my surprise the same result.
The bulb is actually working but not putting on the max amount of light.
It glows very dimly, like it only getting a few volts.
Kinda of stumped.
First time I ever seen this from a car head light.
I thought they either work or they don't.
Any ideas?

Thanks

na when a head light gets old it will go dim like that sometimes or you could have corrossion in the light socket