So I'm having an issue with running lights they worked when I got my 99 1500 but then they went out I was messing around with the fuzes and they cam back on but then I turned the truck off and went to start it again and they stopped working well I just got them to turn back on again while I was messing with the bulbs but it did the same thing I turned the truck off and turned it over again and they stopped working I've changed the switch 3 times and it's not working I don't know what else it could be

 

Check grounds.

 

where should I be looking for the grounds?

 

If you don't have one yet, get the service manual for your truck from here. Wiring diagrams are in section 8W.