Scott64pw
Member
I’ve got a 21 powerwagon. I just noticed the air conditioning heat is pretty poor for the first use in the winter. Anyone else had this issue? Fix?
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Poor heat output
- Thread starter Scott64pw
- Start date
Scott64pw
Member
Yea….That’s what I’m worried about. You bring up a good point. I need to check the passenger side.
Scott64pw
Member
it looks like it’s the drivers side actuator. The passenger side is hot and the drivers side is cold. Where is the actuator supposed to be located?
It's supposed to be up and forward of the two white gears (one has a rod connected to it), look up from the driver footwell towards the front of the console close to the firewall.... I haven't found it yet, fwiw
Scott64pw
Member
I guess you have to take the whole dash apart to replace it?
SolidAxleorBust
Well-Known Member
Depends on the actuators. One is reachable, the rest require a gutting. Not the hardest dash to peal apart, but I did all the actuators, a door that was failing and a Heater Core while I was in there.
Docwagon1776
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Flush your heater core first. By far, the more common failure on 6.4L trucks is clogged heater cores and the first symptom is less heat on the driver's side.
Driftwoodsvt
New Member
Clogged heater core after only 4 years? That's not cool. Bad design?
Docwagon1776
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Small passages and sediment. It's debated if it's casting sand or precipitate from the coolant.
Scott64pw
Member
Thanks for the knowledge......How do you go about flushing the heater core? I took to dealer and they are actually saying its the heater core. They recommend replacing the heater core and tearing out the dash for that..... a pretty penny.
When they were running code search it actually started putting out hot air. I was kind of thinking it was actuator calibration or something.
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Docwagon1776
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Mechanically or chemically. Mechanically, you disconnect the heater hoses and going against the normal flow direction use a garden hose and/or low pressure air compressor to push stuff out. Chemically you put some RMI-25 in the system, it latches on to the stuff causing the blockage and then deposits it in your overflow tank (which you'll need to vacuum out). If it's really blocked, doing a mechanical flush first then using the chemical flush will have best results.
They sell kits with a plastic tee that you can cut your heater hose and install and then thread a garden hose on. Then you just clamp it in place to "repair" the cut hose.
Plenty of Youtube videos as well.
johnmyster
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I shoved a short piece of 1/2" pex in a broken off end of a garden hose. The PEX is a perfect fit to the ID of our heater core hoses. Boom, I had a garden hose to heater core flush adapter. Alternate directions and alternate with compressed air to break up debris along with some short CLR soaks.
If there's enough crud in your HC to warrant flushing, it's probably elsewhere too and your HC is acting as a filter. It will come back if you don't resolve. Flush the heater core, and use something like CLR, but don't spend too much time at first or you might unnecessarily perforate your HC. Before putting things back together I'd recommend a citric acid flush of the entire system (prestone sells a citric acid flush product) and then some high volume garden hose rinse of the block, radiator, etc.
Ultimately, use something better than Mopar purple.
If there's enough crud in your HC to warrant flushing, it's probably elsewhere too and your HC is acting as a filter. It will come back if you don't resolve. Flush the heater core, and use something like CLR, but don't spend too much time at first or you might unnecessarily perforate your HC. Before putting things back together I'd recommend a citric acid flush of the entire system (prestone sells a citric acid flush product) and then some high volume garden hose rinse of the block, radiator, etc.
Ultimately, use something better than Mopar purple.
H3LZSN1P3R
You're doing it wrong
Air conditioning heat? You mean the heat… the blend door may be stuck or check your cabin air filter
motorhead426
Well-Known Member
How many miles on the coolant? I've a few recent videos where the heater core was packed with sediment causing a blockage... if it's not a blend door.
Scott64pw
Member
Thanks for the replies guys. The truck has close to 85k miles on it. It's got the original coolant. The dealer says the doors are acting like they should, so I'm guessing the core is clogged. Does anyone know why the heat works on the passenger side but not the drivers side. Is the heater core partitioned with two separate flow paths for drivers and passenger side? I'm assuming they don't have two heater cores?? Does anyone have access to maintenance manual or parts manual for these trucks?
johnmyster
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It's one core. The bottom of the heater core, where all the crud settles, is the part that serves the driver's side. The top serves the passenger side. Let it go long enough and neither will be warm. The end tanks are vertical (on the sides) and cross flow, horizontally.
If CLR and/or air water blasts don't get it unclogged, heater core replacement is necessary. Reccommend starting gently, else you eat the clogs away but you also eat away the core at the same time. I wouldn't use drano.
Recommend flushing entire system if it works, including a hot chemical flush with something like citric acid. Else, crud will migrate back to the heater core and you'll get to do it over again. The HC is acting as a filter for the rest of the system.
Mopar purple is junk beyond (and at) five year intervals, despite what the manual says.
Per Eric at SMA, FSM says you should get 145 F air out of the registers with blower on full blast, engine at temperature, idling with 70 F ambient. Sounds like a 75 deg F rise to me. Mine will make 130 F at the registers at idle, full blower, on a 35 degree day (95 F rise). Before flushing mine was 100 driver side at same ambient (65 F rise).
If CLR and/or air water blasts don't get it unclogged, heater core replacement is necessary. Reccommend starting gently, else you eat the clogs away but you also eat away the core at the same time. I wouldn't use drano.
Recommend flushing entire system if it works, including a hot chemical flush with something like citric acid. Else, crud will migrate back to the heater core and you'll get to do it over again. The HC is acting as a filter for the rest of the system.
Mopar purple is junk beyond (and at) five year intervals, despite what the manual says.
Per Eric at SMA, FSM says you should get 145 F air out of the registers with blower on full blast, engine at temperature, idling with 70 F ambient. Sounds like a 75 deg F rise to me. Mine will make 130 F at the registers at idle, full blower, on a 35 degree day (95 F rise). Before flushing mine was 100 driver side at same ambient (65 F rise).
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H3LZSN1P3R
You're doing it wrong
Its likely due to low flow in the core enough that the blower is cooling the air down by the time the air gets to the drivers side. Its not un common to have a plugged heater core and passenger side heat only.
Scott64pw
Member
Thanks for the detailed information. I have an 07 charger and always use the Mopar red. It has been lasting well in the charger. I didn’t know they changed for trucks. What coolant is a good one?
johnmyster
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Full flush and Fleet Final Charge Pro. It's also red, but no association to mopar orange/red/purple variants. Mopar shot themselves in the foot when they made red that was kinda like orange, and then a different red that was incompatible with the other red, and then a purple that fades to orange/red, which is kinda like dexcool orange.
Five years, flush and refresh.
