i have an early 07 4x4 3500 6spd, with K&N cool air intake and cat back straight exhaust only... when i first crank my truck in the morning with temps under 40degz my headlights and dash lights will go back n forth dem and bright for about 10 or 15 mins... just wondering if i have a problem or if thats normal and just the truck warming up... it runs fine... any knowledge??

 

Its your heater grids cycling on and off. Will do that till it warms up, or you drive it over 20mph. Normal...