I am having trouble getting my custom textures to show up in flightsim. They show up in t GMAx but when I run FS the diffuse color shows not the texture. Any help would be appriciated.

It sounds like you haven't converted your textures from whatever format you used in Gmax to either an 8-bit .bmp or a DXT1 texture. Use 'Imagetool' or 'DXTBmp' to convert your textures so that FlightSim can recognize them.Jim