Malfunctioning Turn Signal

Hello. New to the forums.

The left turn signal on my 1996 Ford Thunderbird LX, V8 4.6L engine, 125000 miles has begun to malfunction.

When I turn it on, the indicator on the dashboard flashes very rapidly. Outside, only the front signal is flashing and rear signal does nothing.

The right turn signal is fine.

I have checked the fuses and the bulbs. They're both working, but I replaced them anyway.

So, now I turn to the forums for help.

Any help is appreciated.