I have a 04 2500 Cummins. I jumped in the truck the other night and after firing it up i noticed the lights were dim and the heater fan was surging a little. The battery gauge was showing just under 14. It stayed there until i drove down the street at which time it came back up to 14.5 - 15.0 volts. I have kept an eye on it for the last several days. Sometimes i start up and it goes straight to 14.5 volts and other times it is well under 14. Is this normal or do i have a problem starting to develop ? I wonder if the batts are getting weak ? Can someone tell me if this is normal or not. I never have noticed the dimming lights abd what not when it came to the batt guage. It never goes out of the green arc on the batt guage. Can someone shed some light on this ?

 

...that is symptomatic of the Grid Heaters kicking on! They will run when the temp sensor indicates under 60 deg. F, was it a bit chilly outside? They kick off over a certain speed, I believe it's 25 mph - which would explain your charge indicator returning to normal as you started moving down the road.

Key: Did the dimming of the lights and movement of the charge indicator act in a cyclic manner (dim....bright....dim....)?

 

yes the lights did seem to cycle dim bright dim etc. So did the fan. Well i guess that is good. I just never noticed it before.

 

Good grief, near 100 degrees and they are concerned with the heater grids... Oh well.

 

Have the Alt. , batt. and starter load tested then you'll know whats up , and its like a check up, do it every 6mnts. and the likly hood of a brakedown will deminish , and the Alt. , starter will last a lot longer if you replace em just before you have to jump start. a lot of part stores will test for free and a tow in my nieghborhood is about 150.00.

 

Lucey lives in the FAR North. It never gets to a 100 degrees where Lucey lives. This is the grid heaters cycling and is absolutely normal They dim the lights because it draws so much current (I believe its like 90 amps). I would think at this time of years its getting down to about 30-40 F at night.

 

Why?? This is a 2004 - its a NEW truck

 

Check out this link OR look at the very first post in the HELP section.

https://www.dieseltruckresource.com/...threadid=57485