2001 chevy 2500hd alarm wiring diagram

The keyless unit directly below the steering column has a brown, gray, purple plugs facing towards the rear of the vehicle.

Lock = Light blue (+) in brown plug.

Unlock = White (+) in brown plug.

Disarm OEM alarm = Light green (–) in purple plug.

That is the same color code on the wiring diagrams I have.  They are not working.  I checked them via toggling the door switch and using the alarm remote.  I found that even the horn trigger wire is in a different plug.  There is no purple plug at all.  There is neutral,grey,brown,lt. blue and a black plug.   I have never run into this before, usually they have everything right there to tap into.  All ideas are welcome......And yes my meter and test light are working.....lol

That sounds like a 2003 rather than 2001. If that's the case then . . .

There are three ways to do door locks on this vehicle.

The first one is to do reverse polarity in both front doors on the tan wire (Unlock) and the gray wire (lock). Note that its impossible to rearm this way!

The second way is to open the factory door lock switch and then solder wires into it. This way you will be able to control all doors including arm and disarm. Set for double pulse unlock.

The third is with a data module. Like on the application guide on this page.