If your wood splitter won't split wood, there could be a few different reasons why. The first thing you should check is to see if the blade is dull. If the blade is dull, it will not be able to cut through the wood as easily, and you may need to sharpen it. Another reason why your wood splitter might not be splitting wood could be because the log is too big. If the log is too big, it won't fit into the opening of the wood splitter and therefore can't be split. Finally, another reason your wood splitter might not be working properly is because there isn't enough hydraulic fluid in it. Hydraulic fluid helps power the piston that splits the logs, so if there isn't enough fluid, then the piston won't have enough power to split the logs.