2003 silverado 2500 adding lock actuator

I am wanting to add a lock actuator to my tailgate and purchased a vehicle specific actuator from Auto Loc part#HMGTL2. Its a 2 wire actuator. I looked at the factor wiring diagram but am unsure how to hook up the additional actuator to the factory keyless entry. Any help would be greaty appreciated.

I think that there is a DataBus system on that vehicle.  If no one else can tell you where to get a negative pulse from the vehicle, it will be possible but you will have to run 2 wires into one of the doors and parallel the actuator in the door.  If some one can tell you where to get a pulse off of the factory alarm, there is a diagram for the relays on this site.  If someone posts that info I will post the diagram.

i am an idiot is correct in that there is possibly data bus locking on your truck.

You will want to connect those 2 wires directly to the factory lock/unlock actuator leads which will be gray(lock) and tan(unlock) regardless of where you get them.

The location of the wires will depend on whether or not your truck has a.) crew cab and b.) power windows

1. Crew Cab - you can connect to the motor leads in the harness to either rear door.

2. Non-crew cab, no power windows(aka base model) - you can find the motor leads in either front door harness. Connect to the driver's door if you want it to unlock on the first press of the remote, passenger's door for unlock on 2nd press.

3. Non-crew cab, with power windows(aka uplevel model) - on these trucks the actuator wires are entirely within the front doors. The door modules (which contain the power lock/window switches) receive a data signal from the Body Control Module and operate their respective actuators. Therefore you'll need to run 2 wires in the door to the door module if your truck is like this.

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