It's finally cooled down a bit here in Texas, been in the mid-high 40s the past few days when I'm headed to work. I've noticed when I first start up and am Idle, the headlights and gauge lights will dim, and the battery gauge will drop, then it will spike back up and the lights brighten back up. I assume this is the grid heater kicking on/off, but I just wanted to make sure it's normal and I don't have an alternator problem or anything.

 

Normal as normal can be. Under 66 degrees the truck will cycle the grid heaters until you get above 19 mph.

 

Thanks a ton!

 

mine doesnt cycle or come on unless its below 50 Even then it starts right up as I have done it by accident. Maybe the 07's are different?

 

havent noticed mine but i will pay more attention now to see

 

Dang. I was thinking the exact same thing the last couple days. Wondering why it was dimming and surging.

I waited yesterday and it started up fine but today I forgot and it still started up just fine.

 

Yep, totally normal.

 

Not sure if the '07 is different. It's in the owners manual. The 66 degree thing is not the temperature outside, it's the temperature inside the motor that determines whether the grid heaters come on.

 

I understand that its the internal temp of the motor But even leaving it overnight when its 55-60 the pig tail dont come on and the grids dont cycle on my truck. It only does it when its in the mid 40s or lower at night. No matter like been said its 100% normal the grids to cycle even after the motor is running.

 

Thanks for posting that question and to everyone who answered it. Saved me from having to start another thread as my truck has done just that on a cool morning startup the other day. I kinda figured it was a heater cycling, but wasn't sure.

 

Yes, the dimming lights is normal. In fact if you read your owners manual you will see that it states that the lights dimming durning cold temps readings lower than 60 degrees is the result of the grid heaters cycling. This itopic is also was sticky note at the beginning of this forum and has been asked by new owners all the time .

Shawn

 

That's funny. Ditto, was worried alternator was crapping out when cold.

 

God Bless Texas & Dtr

 

See this post...or the hundreds of ones just like it:

and a sticky too!
https://www.dieseltruckresource.com/...d.php?t=121337

But I too asked the same question....just a noob thing to do i guess


chuck

 

I had the same question just last year when I got mine. Perfectly normal. This place is a priceless resource for info. Let's keep it up!