"Tach: check the gray wire co
"Tach: check the gray wire connection on the neg. side of the coil and behind the gauge. Spray a little WD-40 into the switches and then exercise the switches on the rear of the gauge.
Speedo: Remove the air hose on the pitot tube and blow through it to see if the gauge moves. If there is no back pressure when blowing into the hose then the hose is cut. If there is backpressure and the gauge won't move, check for a kinked hose or just install a new hose.
You can remove the hose from the gauge and install a short hose to it and blow into it to see if the gauge moves before installing a new hose."