I have a 2007 5.9 CTD and in the morning especially when it is cold after I first fire up the amps on my alternator go above 14 and then it shuts down and goes back to normal range. It does this for about a minute before holding at the appropriate amps. Is this normal? Has anyone else come across this issue?

 

The grid heater cycles when you first start your truck. This is what causes the lower voltage at first. It is normal.

 

Yup, what he said

 

Yup what they said ^

 

my 07 6.7L is doing the same thing.

Key on its 12V, after i start the truck about 3-5 seconds later it jumps to 14V and the interior lights become brighter.. But then after about 30 seconds it drops back down to 12V and the interior light dim again, then a few seconds later back to 14V then back to 12V... You get my point..

It did this after a 1 hour drive then i stopped for gas then started it back up, and it did it again when i got home just now and restarted it.


So this fluctuation is normal then?

 

yep, normal

 

I think they should put a huge yellow sticker on the dash for people when they buy their trucks that say this is normal since nobody reads the manual to know this. I cannot tell you how many Dodge guys walk by and tell me there is something wrong with my truck because the grid heaters are cycling....

 

bought my truck used and does not have a manual, but this place is a wealth of information as i noticed this tonight. i thought my truck was possessed.