Engine/Transmission (1998.5 - 2002) alternator

[Tractorat]

It may have always been like this, and I just never noticed. But, Ive noticed recently that, when I first start the truck, the alternator needle is to the left, almost right on the low "normal" hash mark. After a few seconds, it goes right to the middle where it should be. I hope this isnt an indication of the alternator going bad. Can anyone enlighten me ?



Thanks,

TRat

 

[DWeiler]

Its your intake grid heater cycling on and off ,---"NORMAL"---all do this,every time you start your truck in cooler weather. Should last fore about 3 min. Do a search on the subject and be prepared to read for hours.

 

[Tractorat]

Thanks,

I thought of that, and thats probably it. But, I dont remember it doing that before, and I would have expected the needle to bounce up and down, rather than just starting out low and then going to normal. Also, I had the block heater plugged in all night (I dont know if that makes a difference)



TRat

 

[DWeiler]

Mine moves slowly back and forth,even affects the fuel pump(Airdog) pressure by about a couple of PSI from the current draw of the grid heater. When i first bought this ride i called the dealer and asked what the heck is going on ---this from a gasser guy before my diesel. Oh YES and pre TDR days too.

 

[jkern]

it is not the alternator going bad... the reason you haven't seen it before is because the batteries are probably getting a little old and weaker. the grid heaters consume such a large amount of power that the alternator cannot supply it all... therefore the batteries act as a reserve to supply this power. when the heaters cycle on you see this as a lower voltage event on your meter. with a new set of batteries you wont see as much variation. keep in mind though... it DOES NOT mean you need new batteries. I ran my stock batteries for 9 years!!!

 

[Tractorat]

Thanks,

Batteries also occurred to me. My batteries are 6 years old now. If it was summer, I might not worry. But, I think its going to get cold this winter. And if I go up to the mountains, it might be a good idea to have batteries that I can depend on.



TRat