25-26 Block Heaters: Check your trucks!

[KJP]

Same issue with my 2026 3500 - unconnected cable was clearly visible right next to the passenger side battery - all of 3 minutes to pull the shipping plug off of the heating element on the engine block and attach the cable. If there was any benefit, it was discovering the right size step stool to gain access to the engine compartment

 

[Farmatt]

I've looked on my 26 but I'm not seeing it. Just got in to drive min3. Oil is 28 and coolant was 48F after being plugged in all night. Outside temp is 24F but it got down to 18 i think last night. Would those temps be higher if it was plugged in?

 

[mbarber84]

I've looked on my 26 but I'm not seeing it. Just got in to drive min3. Oil is 28 and coolant was 48F after being plugged in all night. Outside temp is 24F but it got down to 18 i think last night. Would those temps be higher if it was plugged in?

If it was plugged in all night, your coolant temperature should be 100°F. Your cord is either not connected, or your block heater element has shorted out. (Assuming you have good power on the extension cord)

 

[Farmatt]

Sure enough mine isn't connected. There's a rubber on the plug connection. It's balls cold out and can't pull it indoors. I'm not seeing a separated plug around the heater plug.

 

[mbarber84]

Sure enough mine isn't connected. There's a rubber on the plug connection. It's balls cold out and can't pull it indoors. I'm not seeing a separated plug around the heater plug.

If you have the plug end under the bumper then the cord is in there somewhere. Just disconnected. Have to trace the end backward into the engine bay and see where it leads.

 

[Farmatt]

I found it. Does it run ontop of the turbo intake? Seems like the only way it can given how short the cable is from where it's clipped onto another wire bundle.

 

[LoneRanger]

Ram put out a bulletin back in May, but I missed it. Happened to notice recently that a lot of people are posting pictures of their 2025+ Cummins trucks, and it’s very apparent that the block heater cord is not connected to the element in the block.

If you have a 2025+ Cummins powered HD, check your truck! Make sure the block heater cord has been fully and properly attached to the heating element that is threaded into the engine block. You’ll find it on the passenger side of the block, below the engine oil filter housing. Seems like the engine end of the cord is usually hanging between the oil filter housing and the EGR.

This is supposed to be something that dealerships address during the PDI (Pre-delivery Inspection) but, unsurprisingly, it seems to be an often overlooked item on their checklist.
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Wow, glad I tripped onto your post...same issue with my 2025 I bought in early '26. Thanks for the info!

 

[LoneRanger]

I found it. Does it run ontop of the turbo intake? Seems like the only way it can given how short the cable is from where it's clipped onto another wire bundle.

That's where I had to run mine...impossibly short cable, so no other choice it seems. Difficult to know if I got the plug in correctly, as I was fumbling with the tight squeeze. Guess I'll know first time I try to use it.

 

[Farmatt]

Got mine plugged in this morning. Put the ground blade facing up. It's been plugged in about an hour, oil and coolant says it's 70. Ambient air temp is 28.