Heat issues

[nedz19]

Been battling this issue for a while now, hoping someone may have some insight. I've read several forums and still lost.
When my truck is at operating temp (fluctuates around 188-192) it still blows just luke warm air. It is definitely cooler from the defrost than from the vents and floor. If I turn the climate know from hot to cool and back it will have a short, hot blast then cool back off a little. I've flushed the heater core several times, and the hoses are the same temp. I've replaced one of the actuators behind the dash just below the radio. There are no clicking or banging noises. Just not sure what to look at before spending a couple grand at the dealership...

 

[Joshwaa]

Not really sure about the cummins but do you have a valve that controls the coolant going to your heater core? If so that's what I would check first. Then start checking all the air flow gates in your dash.

 

[ckleinfeld]

Just to confirm, I would remove the glove box and makes sure the blend door actuator is going to full hot when you set the knob accordingly. It should look like the attached pic.

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[Gary2]

5-6 years is about how long it took for my 03 to require a new heater core. It didn't leak but it must of had enough sediment . It would be warm at first but not long after driving the temp dropped. Try flushing if you find no issue with the doors. If flushing makes an improvement figure on a core change in your future. I got mine improved enough to get through the rest of the winter but could feel it losing it by early spring . Dodge Jeep Ram have only had issues with the doors, core and evaporators for the last 20 years that I know of so maybe in the next 20 they may act on it if they even care.

 

[nedz19]

Just to confirm, I would remove the glove box and makes sure the blend door actuator is going to full hot when you set the knob accordingly. It should look like the attached pic.

Sent from my SM-G965U using Tapatalk

Checked this and numerous other things. Still at a loss and freezing my butt off. 9 degrees this morning and couldn't get get any air warmer than 80 degrees