I have a VDO Top Eliminator tach that has a built in shift light, and I also have a shift light that came off a Sun tach. The shift light has two wires and the Tach only has one for a external shift light. Can anyone help me on which wires the two from the light goes too. I have 5 wires coming from the tach there is a green one., red, white, black and a yellow one. The yellow is for a external shift light but I wonder if it for VDO only?