Morgans tend to be older than most other cars, hence components also age. Electrical connections, even undisturbed, can get corrosion/ tarnishing. They might look ok and , as described above, simply unplugging/ refitting does a clean up of the mating surfaces.
Bullet connectors in exposed, harsh environment areas such as under front wings are particularly prone. When I had front light issues on a 13 yr old Mog they were seized solid. Spray was constantly hitting them. Replaced with new spade connectors sealed with shrink fit tubing.
