The tach, speedo and speedo sensor are fed hot from the EHC by the power up circuit. If you do not have a neutral light or tach power then you probably didn't notice that you do not have oil pressure indicator either. If this is the case you probably do not have power on the red power wire on the tach connector or have a bad connection as already mentioned by Curtis. I think there is a 8 pin connector under the tank also. The info I am providing pertains to a 06 k9 but I think they are similar or the same.