I have a 2007 SLT Mega cab with the 5.9 and love it.

On coldish days after I drive away the lights well dim, the heater fan lags, then kicks back to full power and after its warm and moving it stops. Its almost like I have a bad battery or altenator. When I asked at Dodge they told me that it was fine and lots of trucks do this because of some air intake heater.

Has anyone else looked into this and if so what came of it?

Thanks for the help see you on the road.

 

Normal...its the heater grids cycling.

 

Click Here for an explanation.

 

The intake grid heater should only do that for 3 minutes after startup. Check the owners manual and the drivers side visor

 

Normal. The grid heaters will cycle around 55 or lower, and they draw a lot of power. They will do this while idling until the air intake temp hits a certain temp, or until you hit 20 MPH.

Depending on where you live, you can do a grid heater delete and this won't happen. I would only suggest that for a tropical climate, somewhere that you don't see under 30 (that's a conservative temp) and can plug your block heater in. A well cared for Cummins can start at zero or below without assistance.