Wierd Voltage Issue

[Bernie]

I've had my 2006 about 3 months and have about 15k miles on it. On the last leg of a long (5k mile) trip we stopped at a Super 8 to get a few hours of sleep.



In the morning I did not get a wait to start (which is normal on my truck if the engine is at all warm or if it is warm out). I left the key in the on position for about 5 seconds prior to starting (to allow fuel pressure to build), and then started the truck as I normally would. It started right up.



For the first 10 to 15 seconds, the voltage was all over the place and the lights were dimming. When I gave the truck some throttle to help the alternator charge, the problem got worse. After the voltage seemed to settle down we then drove the last 6 hours of of trip with no problems.



When I got home I dropped the truck off at the dealer for this problem and weak AC at idle. The AC refrigerant was a little low, so the re-filled it. Per the dealer the voltage issue is that Cummins Turbo Diesels "just do that". Nobody at the dealer could give me any more information as to why.



That was two weeks ago. Now my airbag warning light is on. I am now wondering if I have a larger voltage problem that my dealer doesn't want to deal with.



Does anybody have experience with this or a similar problem?

 

[TSpecht]

The grid heaters firing cause the lights to dim for the first 2 minutes after initial startup, or until you exceed 18mph, whichever comes first. Sometimes the grid heaters run after engine startup if it's cool enough out for emissions reasons, even if the computer didn't figure it was cold enough for the wait to start lamp/preheat cycle...

At least that's what mine does...

 

[JApol]

grid heaters are on for about 10-15 seconds when the engine is running. But how far was the volt meter moving? couple of volts or was there excesive movement of the meter?

Now you really have a reason to turn the truck into the dealer to get the airbag fixed.

 

[Bernie]

I just got back from the dealer. The passenger seat belt pre tensioner is throwing the code that is turning on the air bag light. They have ordered me a new seat belt and I have to go back when it is in.



I've got a good dealer (Bob Johnson's in Springville, NY), but I'm still a little worried this is the shape of things to come (electrically). I am historically a foreign car and truck owner but I needed a truck to tow race cars with, so I went Dodge. I'm three months (15k miles) in to ownership and it has been back to the dealer for service twice.



The voltage was all over the place but I didn't make a mental note of the lows and highs. I would say between 9 and 15 volts.

 

[rbattelle]

That's not the grid heaters cycling if it was bouncing the needle around. It's either a faulty gauge or something in your charging system is shorting out.



Ryan