Ok, my truck after having the headlights on for a while, they will start to flash on and off iradically. Im figuring its the switch but you never know, thought I'd ask if any of you had similar issues.

Sent from a real cummins, a 1st gen!

 

There's a thermal breaker built into the switch. When it gets bad and starts to heat up, it'll break and make like that.

 

sounds like it is time to put your headlights on relays.
https://www.dieseltruckresource.com/...d.php?t=176263

 

Check your body ground at the core support. I tightened mine up and they started working right again. Which makes absolutely no sense, because when I put the batteries in, I found that I had doubled up my grounds. So the core support is grounded twice. I dunno, but it's the cheapest place to start.