1999 dodge ram 2500.looking for back up wire color under dash.to hook up back up lights,to factory lights.tried to check with test light couldnt find. right now the rear aux lights have 12 volts all the time.i can turn on the back up lightsgoing down the road wich i wouldnt do.

 

on my 02 3500 the wire is purple in rear.

 

yeah thanks i new theres was the taillight wires,i didnt want a bunch of wires running to the cab,i was looking for the wire under the dash to trigger the relay when in reverse,to light up my back up lights when i got the truck acouple months ago the old owner had run the wires to the reverse lights along the frame rail.attached to the fuel lines and one wire was 12volts all the time no fuses.so i rewired it,put in a fuse and relay and new grounds.thanks for the input