I got an 06 dodge 2500 with 11,000 mile. The charging system kicks on and off about every 5 to 10 sec.Voltagedrop to 12 volt back up to 15, lights go dim heater fan motor will slow down and speed up.And not all the time. I took it in to the dealer today. They said that it is the eng. intake air heater is turning on and off and there is nothing wrong with to charging system. And that this problem is very comon with the cummins in extreme cold weatherand has been since 1989. Is this true or do i need to find a new dealer.

 

How cold was it outside?

The heater grid pulls A LOT of power. If it is less than 60 outside yes it will come on...and yes your lights will dim...and yes the volts will drop. There is nothing wrong well unless it's not doing it but that is a whole different story.

Anyhow.....here is a collection of cool threads will all sorts of info on the great CTD's & cold weather....happing reading....welcome to the forum.....can't wait to see more info on the truck

https://dodgeforum.com/m_1098880/mpa...tm.htm#1098880

 

8 deg in the day -25 at night. I am in north eastern Utah. Thanks for the link i will go check it out.

 

Grid heaters cycling on and off, Normal for a CTD.

 

I new that they cycled on and off i thought that when the eng got to operating temp. that they would stop.

 

Since it does not get very cold in Georgia, I am really not sure how long it stays on after the truck is warm. But I would have to think it has to do with how cold the air is where you are. Maybe some of the members from colder areas can shed more light on how long theirs stay on....

Below is the info out of the service manual..

The air heater element is used to heat incoming air to the intake manifold. This is done to help engine starting and improve driveability with cool or cold outside temperatures.
Electrical supply for the air heater element is controlled by the Engine Control Module (ECM) through the air heater relay.
One heavy-duty cable connects the air heater element to the air heater relay. This cable will supply 12 volts to an individual heating element within the heater block assembly.

If the intake manifold temperature is above 66.09 degrees Fahrenheit, the wait-to-start lamp will not illuminate. Consequently, the intake air heater element will not be activated.[/b]