I have a 2006 dodge 5.9 and when I go to start it the volt gauge is way Down and it kinda drags before it starts. After started the gauge bounces up and down for a little while after it warms up it stays up? Anyone have the same problem if so. Whats the solution

 

lol welcome to owning a cummins diesel!

this is perfectly normal behavior when it starts getting colder outside. Its your grid heaters cycling on and off to heat your intake air to help the engine start and run in cold weather until either the vehicle reaches 15+mph, intake air is over 60*F or engine warms up enough to no longer need the heated intake.

Cummins does NOT use glow plugs like ford and chevy (or most other small diesel engines) just a big heater element between the intake horn and the intake plate on the head that pre-heats the intake air to help burn diesel in cold weather.

The grid heaters draw a heavy electrical load and they cycle on and off by design to not overheat the batteries or wiring. this is the main reason your truck has dual batteries...it doesn't take 2 batteries to start the truck, it takes 2 batteries to take the load of that grid heater during the winter as the alternator can't keep up with it.

 

just food for thought...actually spec for power draw from the grid heater is 220A

so 220A x 12V = 2640W power draw while the grid heater is cycling.

 

Thanks guys. I went and had my battery's tested and one was completely dead. It already starts better ow too. Ya I thought that's what it was is the heater but I didn't think it should drap the volt gauge that far down. But when I start it tomorrow morning I'll see how far it drags it down with the new battery

 

should drop to 12v then back to 14v when its off. mine never drops below 12. if it does, means one or both of your batteries are toast or weak...

 

Ya see it was dropping down to like 8 then going back up

 

05 dodge 2500, installed new alternator and batteries. The volt meter is at about 12 for about 5-10 seconds then it moves up to about 15 for about 5-10 seconds. Is the new alternator bad or is there a voltage regulator issue and where is it located?

 

This is when its running, not off,

 

did you read above?

when it is below 60* outside, this is perfectly normal behavior. it is your grid heater. all cummins engines in the dodges have grid heaters that heat the intake air to help the engine start in the cold.

the grid heaters cycle on and off every few seconds to prevent overheating the alternator/battery because it puts such an enormous power draw on the system.

Cummins does not have glow plugs. Just a heater grid directly below the intake horn.

 

Check to make sure the ground wire for the intake heater is hooked up as well. My voltage drop was so bad my ECM would act stupid and cut out three injectors. Realized the ground had been removed by someone in the past causing a bad grounding issue which caused too much battery draw.