Lighting and/or signalling unit comprising an adapter suitable for being housed in a light module of a motor vehicle

The invention relates to a lighting and/or signaling assembly for a motor vehicle, comprising: - a light module (2) and an adapter (10) capable of being placed and held in position in a housing (8) of a support means (4) of an optical collector (6), - separate means for clamping (44) the adapter (10) against the support means (4) of the module (2) according to a first direction on the one hand and means for adjustment (32) of the adapter (10) in the housing (8) formed in said support means (4) on the other hand, adjustment according to a second direction distinct from said first direction, these clamping means (44) and adjustment means (32) being carried by the module (2) and/or by the adapter (10). The invention further relates to the adapter (10) and the module (2) associated in this lighting and/or signaling assembly.