try putting your lightmap on the colorgain input of your color texture instead of using on the diffuse or ambient. This will really multiply your lightmap into your colorgain.
I´ve a scene in maya with baked light using 2 uv sets, one for texture color and other for baked gi, i´ve baked the light to the 2nd uv set and now i don´t know how to create a multitexture shader, i apply the baked texture to the diffuse slot but i dont know how to tell maya that that slot should use the 2nd uv set how is…