Alternator delay

[Lew J]

I have a 2018 Ram 2500 with the diesel engine. I have a little bit of warranty left. The alternator will often not kick in for 25 to 30 seconds upon first starting. The gauge will read 11 volts and not budge during that time, then finally move up to around 14, and then be okay for the remainder of the trip. Dealer service departments claim this is normal. Since they are often untruthful, what do you think?

 

[tron67j]

Alternator will generate power as soon as it starts spinning. Unless there is some type of clutch that takes time to spin up (which I have never heard of on a alternator, but interested to hear if this is a thing now) I would say the problem lays elsewhere, like maybe the gauge. The only way to check is a voltmeter when you first start it, at the output connection.

Additional thought - does a diesel take so much power for plugs as they warm up that the draw is so great to register on the gauge?

 

[wallacemf]

I have a 6.4L now, but my previous trucks were CTD. Yes, when the intake grid heater kicks on, the voltmeter will drop significantly. It cycles on and off, so you will see the voltmeter go up and down when that happens.

 

[tron67j]

Never having owned a diesel myself I was not sure. But I used to drive straights and I was thinking that might cause a substantial draw. Thanks for the information.

 

[Arth]

I have a 2018 Ram 2500 with the diesel engine. I have a little bit of warranty left. The alternator will often not kick in for 25 to 30 seconds upon first starting. The gauge will read 11 volts and not budge during that time, then finally move up to around 14, and then be okay for the remainder of the trip. Dealer service departments claim this is normal. Since they are often untruthful, what do you think?

What he is experiencing is normal for cold conditions. The alternator is doing it's job and so is the grid heater.

What's happening is the grid heater for the diesel engine is being cycle to help maintain smooth running of the engine until it gets up to a warmer temperature. Cummins doesn't use glow plugs in the 6.7 they use a grid heater on the intake side. Since it's cold out the grid heater is cycled on and off for a while and when it's on it's a big drain on the alternator.

In this case the dealer is telling the truth.

 

[CVX20]

Most likely your battery is just getting weaker,so grid heater draw is pulling the bat volt down more and takes longer to come back.Dirty connections at the battery a possible cause also.Did the dealer mention whether they did an alternator output test?Amps not volts.

 

[Gr8bawana]

What he is experiencing is normal for cold conditions. The alternator is doing it's job and so is the grid heater.

What's happening is the grid heater for the diesel engine is being cycle to help maintain smooth running of the engine until it gets up to a warmer temperature. Cummins doesn't use glow plugs in the 6.7 they use a grid heater on the intake side. Since it's cold out the grid heater is cycled on and off for a while and when it's on it's a big drain on the alternator.

In this case the dealer is telling the truth.

As he ^^said this is normal. My 2017 does the exact same thing.

 

[tourrider]

I’ve seen mine do it too.

I figure it’s a low priority task for the computer or data traffic. There’s a lot of stuff going on at startup, and the queue is probably prioritized.


Sent from my iPhone using Tapatalk Pro

 

[miles01]

My 2001 diesel did it too, had it for 11 years and did it every winter