The ignitor cable is typically not failing only if someone damaged it. The ignitor glow plug may be defective and is worth trying. You may also increase the H2 flow and see if the flame ignites. That would indicate either the H2 gas is diluted by air or the jet is partially plugged. Please, clean or replace the jet. In some cases the gases are so clean that the signal drops below the lit offset. Then you need to lower the lit offset.