[VetteVet]

you should have three wires to your lights. A purple one to both lights, a light blue one for the left turn signal and a dark blue one for the right turn signal.

If you have power on your wires then lack of ground could be your problem especially since the lights are in the hood. It may not be getting ground to the cab and back to the negative side of the battery. Try running a jumper wire from the battery negative battery terminal to one of the light sockets the with the parking lights on. If you get a light then the hood hinge is not grounding to the cab or the cab is not grounding to the battery.

You might test it with your test light by connecting the light socket and the negative battery terminal. If you light doesn't come on then there is no ground connection between the hood and the cab.