The passenger side front turn signal on my '93 wagon isn't flashing. The passenger side run lamp and head lamp both work. The passenger side rear signal is flashing quickly indicating front bulb failure, but front bulb replacement did not fix the issue. Driver's side is 100% functional.

I'm concerned that the issue may be related to the wiring inside the fixture or the fixture itself but it is not clear how to access this part of the car, as its entirely enclosed by steel and the headlamp fixture. Do I need to fully remove the headlamp fixture to get in there? Are there other troubleshooting steps I should take before doing that? Thanks!