Dimming Head/Interior Lights???

[IdaH.O.Train]

I don't know if this is normal or if others have experienced the same problem. When my truck is running, usually more noticable when at idle with the interior lights on, the lights seem to flicker from bright to dim and back. Has anyone else experienced this? It almost seems like a switch is being triggered, which is causing a change in the voltage. Dunno.

 

[Archive]

That probably only happens when you have just started the truck, and it is cold out. What you are noticing is the result of the grid heater cycling on and off. The heater draws enough juice to cause the lights to flicker. This is normal operation.

 

[Hummin Cummins]

Not sure if the new ones are the same, but its probably the intake heater cycling on and off. Does it only do it after "cold" starts? then quit after warming up?

 

[RACE427]

Heater grid current draw

You are seeing the results of the large current draw and voltage drop caused by the cycling of the intake heater grid necessary to warm up the intake air charge. It is the main reason why Diesels are equipped with two very high CCA rated batteries. Other Diesel engines use glow plugs instead of the heater grid found on Cummins Diesel engines. Hope this helps.