one of them is more than likey an early build. some 02's have 2 connectors on the backside of the headlamp switch.
the 2 way connector is the 02's fog lamp control and ground if i remember correctly.
and next to the 2 way connector is a 14 way.
your 02.5 - 03 whatever it is has only an 8 way connector (from what i am reading)

 

Correct, but I had to check anyhow

 

so you couldnt have swapped headlamp switches to verify its your switch?

 

Switches are identical, put mine in the company truck and all lights worked. Put the one of the company truck in and no low beams. Identical plug ins on the back but yet mine worked when I installed it in the company truck