[sntrym95]

On the 2000 1500, there is a headlamp relay in the underhod fuse box. Being that you have a 2500, I'm not sure which fuse box they used, so there might be one in the underhood fuse box. If it's the older fuse box like the 88-98, then it won't have one and all the voltage runs through the switch and the breaker in the inside fuse panel.

So if you have the old fuse box, check the breaker in the panel on the drivers side of the dash