I am installing some candle sticks, which are fancy marker lights for the outside of the truck. I want to splice into the marker lights/turn signal so they turn on when the parking lights are on and blink with the turn signal.  the marker lights have 3 wires: Green, Black, and I think its purple with a white line. Which ones would I splice into to get my candle sticks to work the way I am looking for?  Thanks for the time and help.

Are the candle sticks a 2 or 3 wire?

Figure out whick wires are the parking light and the turn signal lights. Tie one wire into each one. It will ground through whichever light does not have power meaning with the lights on it wil stay on steady and then blink with the turn signal.

they're two wire, Ill start splice'n tomorrow! Thanks again, you've been a great help.

For the two wire its as Tom said, one wire to the marker light power and the other to the turn signal power.