Starting Issue...

[Kevin Fowler]

I have a 2018 2500 6.7. Last few days when I have done the Diesel Preheat process ( I live in CA, so idk if I even need to do it every time but I still do), and I go to start my truck it does not start. Clicks and shuts every thing down. I can reset the key and then it will turn it on. It only seems to do it when I do the preheat process. Battery voltage is at 12.5-12.9V. Not too sure my next steps here any assistance would be great.

 

[Burla]

If that is oem battery it is time for replacement. Battery readings are flawed. When you pre heat it you are running amps and cummins take a lot of amps to turn over. I would not bother to pre heat any cummins in CA, unless you were talking northern mountains and temps in the teens. Stop pre heating it maybe you will get some more life from the battery dunno, but at any rate that battery is getting long in the toof.

 

[Burla]

2018 truck likely made in 2017 or earlier and now 2024, no matter where you live it's time.

 

[crash68]

Last few days when I have done the Diesel Preheat process ( I live in CA, so idk if I even need to do it every time but I still do), and I go to start my truck it does not start. Clicks and shuts every thing down.

If the weather is above 40°F there's probably no reason to preheat. You should be able to "Tip Start" the truck, just turn the key fob all the way to start then let the key go. The ECM will automatically pre-heat the engine needed and start the engine.
As for the failed starting, it's probably a bad battery, as mentioned the grid heaters draw lots of current.

 

[Kevin Fowler]

If that is oem battery it is time for replacement. Battery readings are flawed. When you pre heat it you are running amps and cummins take a lot of amps to turn over. I would not bother to pre heat any cummins in CA, unless you were talking northern mountains and temps in the teens. Stop pre heating it maybe you will get some more life from the battery dunno, but at any rate that battery is getting long in the toof.

Thanks, I'll have to check. I've had the truck about 2 years, same batteries. Not sure if they are originals.

 

[Kevin Fowler]

If the weather is above 40°F there's probably no reason to preheat. You should be able to "Tip Start" the truck, just turn the key fob all the way to start then let the key go. The ECM will automatically pre-heat the engine needed and start the engine.
As for the failed starting, it's probably a bad battery, as mentioned the grid heaters draw lots of current.

Wasn't sure if the pre-heat would cause other issues regardless of needing the actual heat.

 

[Kevin Fowler]

Batteries were from 2017. They’ve both been swapped. Shouldn’t have an issue moving forward. Appreciate it guys!

 

[Otto16]

I’m glad you’re able to fix it. I have a problem. Hoping you can help me. I have a 2015 Ram 1500 BigHorn Hemi V8 4X4 and I replaced my old battery with a new one and my truck won’t start. It does absolutely nothing, no clicking, no lights, not anything. Any help is much appreciated.

 

[CanuckRam1313]

I’m glad you’re able to fix it. I have a problem. Hoping you can help me. I have a 2015 Ram 1500 BigHorn Hemi V8 4X4 and I replaced my old battery with a new one and my truck won’t start. It does absolutely nothing, no clicking, no lights, not anything. Any help is much appreciated.

Check that the trigger wire on the starter is fully seated. Maybe it came loose or just broke off altogether.

 

[crash68]

I replaced my old battery with a new one and my truck won’t start. It does absolutely nothing, no clicking, no lights, not anything. Any help is much appreciated.

If you don't even get any lights to turn on, check the new battery with a meter as it sounds completely dead.