1997 chevy c/k pickup truck ext cab 3 door

I was wondering if anyone knows about the door lock switch is it a 3 wire pos or 5 wire reverse polarity? I am adding a keyless entry to the truck and cannot figure it out.

Depends on wether or not the truck had keyless entry from the factory.  If it did then it will be 3 wire pos trigger if not then it will be 5 wire reverse polarity.  Lock should be lt.blue and unlock should be white in the drivers kick panel (or at the fuse box?).

The truck did not have keyless entry from factory,so it must be 5 wire reverse. Thanks.

Also I really dont understand the 5 rev polarity system. From what I am looking at the difference between the 3-pos. and the 5 rev. is that you have to connect the master switch to terminal 87a and the door lock actuators to the #30 terminal on the relay my question is why? I put a continuity tester on terminal 30 and 87a and i am getting continuity. Why can't I just tap into #30 terminal?