Hi and welcome!
Diagnosis and testing info:
turn signal lamps:
https://workshop-manuals.com/ford/mo..._hazard_lamps/
rear lamps:
https://workshop-manuals.com/ford/mo...e_plate_lamps/
Unfortunately not enough detailed wiring diagram info to follow through, but gives you an idea of potential causes.
I haven't been able to access the Mondeo 2007+ wiring diagrams on this forum.