[patrickt]

Remember those front turn signal/running lights have two filaments per bulb. That means two positive wires running to each signal light and one ground wire running to each light. Try disconnecting all four positive wires and then measure for 12v+ on each wire with the headlights on and off when the signals are both on and off. Check with a VOM using a ground other than the ground wire running to the light itself. Always keep in the back of your mind the potential for a bad ground.