Passenger turn signal doesn't blink - suggestions?

I'm not sure when this problem started - someone was following me to work and told me my Passenger rear blinker came on, but didn't blink. The passenger front blinker doesn't come on at all and the instrument arrow for the passenger turn signal doesn't blink either. The Drivers side blinkers both work and the instrument arrow blinks as well.

Has anyone had this problem? I thought I read a post about it before, but couldn't find it when searching. I couldn't find anything about it in the Ford shop manual either. I looked under lighthing and the multi-function switch area and didn't find anything about it.

Yep, there was no bulb in the front (guess I forgot to replace it before when I did some bodywork after a wreck). Replaced bulb and all turn signals function properly