When I had my 260, the healights would cut out intermittently, found out the fusible links were fine, just the spade terminals had corroded. Squeeze them flat a bit with a pair of pliers and then re connect. To check, switch your headlights on, then play with the links. If still no go, check for faulty fuses as some look okay, but are broken behind the metal end caps. It's always easier to check the easy to get parts before you have to remove steering wheel covers etc.
Headlight switches are pretty comon so that can be the last check.