Odd turn signal behavior 124

[clint77002]

I have lived with this problem for almost 2 years but now I have to fix it (we moved to Texas where they still have vehicle inspections). On my 87 300D, the turn signals work fine when the headlights are off. When I turn them on, the right front (passenger) turn signal stays on (not blinking...just steady on). The right turn indicator on the dash is also illuminated (steady on). When I move the turn signal arm to indicate a right turn, no blinking and no clicking. When I move the turn signal arm to indicate a left turn, the left turn signal blinks and relay clicks as it should.
What is going on here?

Thanks,
Clint