The fans in my 1999 Beetle will not run. I have checked the fuse, it is good. I have tested the fans - by running a wire from the battery to the each fan. Each fan runs when I provide 12 volts. So I know they are good. All the hoses get hot when I run it. I also changed both temperature sensors out with new ones but the fans still won't come on when it gets hot. Why not, what have I missed? What is my next move?