Does anyone know how many amps a healthy grid heater should be pulling?
My problem is that when my grid heater activates my truck kicks out a 2149 and runs on 3 cylinders for 10 seconds. You can read about everything I have changed out on the post P 2149. Thank You, Grant.

 

Cant say for sure on an 07 but my 01 service manual for the 01 is 90 amps per grid for a total of 180 amps between the two of them.

 

So a 180 amp draw on a 135 amp alternator will show a negative charge, as it cycles again shows a positive charge at around 14+ volts;;

 

And that with the alternator at idle so no way it is putting out 136 amps though even high idle didn't make a noticeable difference. The two batteries aren't there for nothing strictly for the grids no other reason for them. On the 01 it was max 30 seconds wait to start for the grids then they could cycle for a max of 180 seconds or you reach a speed of 22 or 23mph.