Lux T10-1143SA. I installed it by the instructions, but doesn't work. Can anyone help? This is a heating and cooling thermostat

Did you try this?

http://www.menards.com/main/store/20090519001/items/media/Electrical/Lux/Install_Instruct/52015_T101143SA_ENG.pdf


NOTE;
If you have an electric system and the blower does not operate after installation, find the factory installed yellow wire currently attached to the “Y” terminal and move it to the “A” terminal on the sub-base

Did you turn off the main power to the furnace before working on the stat wires? If not, you may have blown a fuse in the furnace or fried the control transformer.