Need electrical help - turn signal / park lamp

[68bowtie]

Been trying to troubleshoot this and can’t quite figure it out. 1970 chevy driver side turn signal/park lamp won’t light up at all as a turn signal and will only light up slightly (very dim) as a parking lamp.

Details:

- New bulb works (tested on other side)
- Turn signal and hazard flashers both working
- When I turn on the hazard lights the pass side flashes bright, driver side flashes very dim, both dash green lights flash, and both tail lamps work fine
- On the wiring diagram these are pretty much two separate circuits so I figured it’s a ground problem, so I removed the housing and wire brushed the contact points with the grille and inside the socket and no change.
- hooked a test light inside the socket and I get a light when parking lights are on but nothing for turn signals.

Wondering if anyone has any ideas???

Does the flasher circuit use the turn signal or park lamp wire? I suppose I can check that with my light...