Did you try swapping the cables on the splitter? Use your old TV, and the old coax (that you know is good) and try both sides of the splitter. If you get a good picture then the problem is the cable you made. Either try making a new cable, or go buy a premade one from Wal-Mart. The coax the installer left is going to be Rg6. If the connectors you bought do not state they will work on Rg6 then you have the wrong ones. Also it is very hard to strip coax properly with out a stripping tool. Unless you have the tools to do it properly I suggest you just go buy a premade cable.