Been there, blown it up, bought a Vantec...

If the servo leads conduct electricity i dont see why they wouldnt work.

Have you got the ribbon wire that goes from your speedo to your interface the right way round? its possible to connect them up backwords and they wont work at all..try turning them round.

Due to the fact that your red light is on shows that your in failsafe mode. What you got powering the board? It needs around a 9v supply for it to run.