[pciley]

If your truck lacks a photo sensor on the dash as described above, more than likely you don't have that portion of the harness prewired in the dash to accept the sensor. If that's the case, your BCM will not know what to do with a sensor if you installed one and got it wired somehow, your BCM is programmed to not have the sensor. Hopefully you do have the sensor though as installing one would probably be VERY expensive (new dash harness $$$$, new BCM $$$, photo sensor $$).

btw. Do your headlights come on automatically? I guess that would tell you if you have that sensor or not.