You can go to the dealer and buy the relay for DRL but only if you have a truck with the right main harness in it (i.e. Canadian trucks), otherwise you have to wire one up yourself. I believe all of the trucks that went to Canada have the correct harness. Most aftermarket modules will not work on the truck either because the headlights on the truck are negative switched. With the lights off check all three wires on the lamp with a test light and you will find that all three wires have power and if you ground one of them out the lights will turn on. I wanted to have DRL's on my '99 and all I did was use a relay to provide a ground on the lowbeam wire and powered the relay off an ignition feed. All you need to do is tap into one side and both of them will work.