cold start..
 

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??:humm:

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