My 95 has the power mirrors OEM, the connector is a flat three wire setup, I had run the other two wires, the turn and the markers to a small clearance lite to the outside of the OEM mirror to be seen when changing lanes etc. The mirrors that I wanted was the 4th gen heads with the bigger mirrors and the other spot mirror, of which was in the 98 and on selection which has the five wire configuration. Three to run the mirror and two for the heat, of which was mostly standard 98 on to the 02's. Which was a stock item at the time. So as mentioned, I sourced from the wrecking yard the plugs needed to do the wiring with out doing a lot of splicing, making a plug and play set up. I found a 94-97 male plug and both male and female plugs 98-02 for the new mirrors which has the five wire female plug attached, along with the wires to run the turn/ running lights. I haven't connected the heat yet. This is how I had to do mine.
Now the question is do you have power mirrors now or are they the manual? you may have the wire harness in the door if its a late enough model. The only way your going to find out is undo the top screw and have a look down inside. The control knob is going to be your biggest problem if you don't have that, that's going to be a problem. you would need the whole harness and be a master mind to figure that one out.
Your question-- yes mine was of course, No totally different configuration as mentioned above.
Good luck.
What is your truck?