monster tacho

[GRUNTN]

ive brought a new tacho and its not auto meter but the old one is when i cut the old one and put gree2green black2black red2red on the new one i noticed the white wire in the dash and so does the auto meter gauge have white wire does any1 know where this white wire should go (all the wires on the new 1 are hooked up it has red, green,black,2 4 the shift light also do i turn the headlights on or just accessories (the auto meter i had hook up by an auto elec) done same gauges on diffrent cars but they all had white