Engine/Transmission (1998.5 - 2002) Why do my grid heaters stick on ?

[JPLB22]

Now that it is pretty cold here I plug the truck in every morning and the grids do there cycle. But I also like to ramp up the idle a little bit with my foot. I will take it to around 1250 rpms. But when I do that my lights go dim and my volt meter starts dropping. It doesn't matter how long I hold the idle up, the grids just stay on without cycling, if I let off the pedle with my foot the grids go back to there regular cycle.



I figure it isn't too good for the batteries for this to be happening. I also am now hesitant to buy an aftermarket idler, I don't want the grids staying on for 2-3 minutes strait.



So why do my grids stop there cycle and stick on when idle is increased ??



TIA



Jeff

 

[ata]

The Grids are not sticking on. When you speed the idle up you are pulling cold air in faster than the grids can warm it so they stay on trying to keep-up.

 

[JPLB22]

So if I was to put on an aftermarket idler, how would I keep the grids from staying on during my entire 2-3 min. warm-up? Or is that even a problem ?



When I increase idle with my foot and the grids stay on I won't let the volt meter drop to the lower line between 8 and 14 volts before I release. But if I kept the idle up for 2 min. I think that volt meter would get pretty low.



Jeff

 

[cpeters]

I don't know if yours is the same but mine will usually not go below the low side of the bracket if I keep the idle up around 1500 rpm. Hope this helps.

 

[ata]

The maximum cycle time for the grid heaters is 3 1/2 minutes. The P. C. M. is what controls the grid heaters. If the vehicle goes over 10 m. p. h. the P. C. M. will shut them down at that speed. The manual also says engine R. P. M. determines activation but I can`t find what the R. P. M. is in the manual.

 

[JPLB22]

I guess I will just keep my foot in to it for 2 minutes or so and see how low my volt meter goes. Hopefully not much lower than yours cpeters.



I did have an '01 for about 6 months, and for the life of me I do not remember it doing this, cause it was cold for part of the six months I had it.



Thanks !



Jeff

 

[snowracer69]

The grid heaters, at least in my '01, and Denis' '01. 5, and my Grandpa's '02, shut off at 20 MPH, not 10 MPH... just a FYI.

 

[ata]

Ok Snowracer69-Cummin`s Pilot I`ll bet if you write or E-Mail Dodge they`ll change the Service Manual just for you because your so special. You think