My 7840 new holland head lights work on main beam but not on dip,no fuses are blowen and the switch lever has been replaced but still no dip beam.Any ideas
Check the bulbs are ok on the dip filiments, check for battery voltage at the connector on the bulbs, test the continuity of the fuse, check the continuity of the wires back to the switch harness.
Look at the wires where they pass the area of the fan belt, if a belt has failed in the past there may be damage to the harness.