My truck fluctuates RPM's about every 10-15 seconds after I first start it, the voltage gauge reads just under 14 and the lights surge, and then as I start to drive, it goes up to 14 until I turn it off and it does it all again.....any ideas? I've tried searching for this on DTR just can't find it

 

Your grid heater is cycling. All normal.

 

Ok, thank you. I just noticed it so figured I'd ask.

 

I stand to be corrected here but i think if the ambient air going in is lower than 32F or 0C, the grids will cycle until you break your crawl and pick some speed

 

It's 36F right now and it just now did it. I can't just let my truck roll, I have to pick up speed in order for the surge to quit if that helps any.....

 

That's normal Dirk. Not sure what speed exactly but as soon as i shift to 3rd it'll stop, being in 2nd and around 1800 rpm, they continue.
It's just so that our combustion cycle is little cleaner rather than blow fuel out the exhaust because it isn't igniting at low temps

 

my 06 will cycle well above freezing. I lasts about 120 seconds or until you reach 20 MPH.