At start up voltage gauge drops

[07cummins]

Hi guys Im wondering if anyone else is having a problem with the voltage gauge when you start your truck? My gauge in the morning and when ever the truck is setting for a long time goes from 14 volts to 8 volts when you first start the truck. It wont stop going upand down until I start going done the road. I do know that the voltage is changing because the lights dim and the idle changes. I do have the puck on 90 horse, would that make a difference? THANKS

[Rick]

Not the puck! It's your grid heater cycling when engine and air are cold.
Heaters will shut off after a certain temp is reached or 17 MPH.
Nothing to worry about.

[07cummins]

Thanks alot for the info Im new to the cummins . This is my first diesel. There is alot to learn about, and you guys help alot. THANKS

[madmanwithmouse]

Not the puck! It's your grid heater cycling when engine and air are cold.
Heaters will shut off after a certain temp is reached or 17 MPH.
Nothing to worry about.

Excpt making sure you have good fresh batterys when its cold, otherwise if the volts stay below about 12 for too long the altanator will cutoff and wont try to charge Then you have to charge the batts and clear the low volt code for it to charge.

[07cummins]

Hi thanks for the info. I will have to check the batteries and keep an eye on the voltage gauge. Thanks for the info.

[Herculou]

I had the exact same thing happem to mine!! Took the Dodge techs 3 hours to figure it out. They kept telling me the computer adjusts to x+y /c= voltage lots of technical junk. It wasn't till the A/C quit they found it.

Turns out a ground wire going to the engine block was stripped out. Basic "old school" problem..........