Hi - it's always nice to include the full clues, letter counts & any you've placed, so that people without the puzzle can more readily help :-)
Both clues are themed -
3d Mother's cross raised (3); (4) - Weir (synonym for 'dam' [mother]; 'mad' [cross, raised])
26a Swerve, failing to keep left (7); (5) - Parry (synonym for 'deflect' - 'l[eft]' in 'defect' [failing])