[paradise]

2003 durmax.
no matter what the outside temperature is....after starting ( when the glow light goes out) why does it take 30-45 seconds for the volt meter to go from 9 volts to 14-14 volts?

doesn't the alternator start "alternating" as soon as the engine turns?

 

[WanaDmxsub]

That's normal.
It was explained a while back. But could be hard to find in a search.

 

[RichLockyer]

Glow plugs actually remain on for a short time after the dash light goes out. The dash light only indicates that it is safe to start.

The grid heater draws a lot of current, and I believe that it too remains on until the ECM is confident that the engine can run.

Add to that, you are topping the batteries up from the cold start....

 

[86underboost]

mine doesn't do that with the dual alt's. With the single, it was just as you explained.

-mike

 

[Diesel_Day_Dreamin]

Looks like duals in his future.

 

[blizzardplowman]

Normal, even with the 145 amp from the snow prep pkg. As others have said duals seem to not show this.