Front marker question

[Defector]

1969 C10, recently resurrected after sitting for 10 years or so. Ran into some grounding issues with some lights, but have a weird issue with the left front marker light.

1. In hazard or blinker, it is not as bright as the right, making me think it's a ground issue. Cleaned the ground on the radiator mount, right behind the marker light, no better.

2. With lights turned on the market doesn't light at all, and the left turn indicator on the dash remains lit.

3. No left turn signal with the lights turned on.

I did replace the bulb. My next move is changing out the housing assembly.

Any other ideas?