2017 Dodge Ram no heat blowing from vents un when heat is on.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Ryan Poulos

Member
Joined
Jul 22, 2019
Posts
71
Reaction score
11
Location
Dallas
Ram Year
2007
Engine
5.7
I have a 2017 Dodge Ram 2500 6.4 hemi 4x4. It has a zillion miles. 343,000. On its 2nd motor with 80k miles.
Outside temperature dropped to 48 degrees today. I had to use my heater for the first time. At full temp, Inside recirc air on, and heat on full red, its blowing cold.
Any ideas?
 

Attachments

  • D2CBF403-7DE2-4D20-80F4-14D80E911E68.jpeg
    D2CBF403-7DE2-4D20-80F4-14D80E911E68.jpeg
    156.2 KB · Views: 18
  • B924AF04-0057-449C-B80D-B956B9B92F83.jpeg
    B924AF04-0057-449C-B80D-B956B9B92F83.jpeg
    125.3 KB · Views: 16
Last edited:

Erikk

Member
Joined
Nov 15, 2018
Posts
89
Reaction score
22
Location
West TX
Ram Year
2016
Engine
6.7 Cummins
2014 2500 6.4 Hemi 130000 miles.

Mine is also running warm ish at 210 coolant temp. I had the core flushed last year and it seemed to help for a bit but it’s back to useless. It looks like one of the heater hoses runs down to the oil cooler so Im thinking that the coolant passages in the oil cooler may be plugged up (lowest point in the system) restricting flow through the core. I’m jumping in here to see if anyone has found that to be the problem. All my diesel trucks had hotter heaters than this 6.4 so there’s obviously a problem. I had the radiator replaced a year ago with a flush and all new coolant, then the core flushed after that.
 

indept

Senior Member
Joined
Sep 10, 2017
Posts
3,213
Reaction score
4,740
Location
South Jersey
Ram Year
2017
Engine
Hemi 5.7L
Are both heater hoses hot? If not then there is a blockage. If so it may be a blend door issue with the vents.
 

crash68

ACME product engineer
Staff member
Administrator
Supporting Member
Joined
Mar 20, 2016
Posts
10,700
Reaction score
16,708
Ram Year
2015
Engine
3.0 EcoDiesel
The blend door actuator location is right at the bottom left of the glove box opening. You should be able to see it move from the side.
 

indept

Senior Member
Joined
Sep 10, 2017
Posts
3,213
Reaction score
4,740
Location
South Jersey
Ram Year
2017
Engine
Hemi 5.7L
The blend door actuator location is right at the bottom left of the glove box opening. You should be able to see it move from the side.
Even if the actuator moves it may still be the issue, I recall reading where the arm moves but the door stays put. The door connection to the arm is the problem. I'm not positive about this, may someone more knowledgeable about that can chime in.
 
OP
OP
R

Ryan Poulos

Member
Joined
Jul 22, 2019
Posts
71
Reaction score
11
Location
Dallas
Ram Year
2007
Engine
5.7
The blend door actuator location is right at the bottom left of the glove box opening. You should be able to see it move from the side.
I haven’t had a chance to remove the cover under the glovebox and look yet.
That said I was in a parking lot waiting to pick up my son and all of a sudden it was blowing hot. And I swear I heard a ‘click/clunk’ right before it went hot.
So is this like my old Dodges where you need to pull the whole dash to do the blend door or is there a heater treater option?
Thank you.
 
OP
OP
R

Ryan Poulos

Member
Joined
Jul 22, 2019
Posts
71
Reaction score
11
Location
Dallas
Ram Year
2007
Engine
5.7
So here’s an odd update. When I parked my truck last night it smelled a little ‘antifreezy’ when I stepped out my door. I looked all under my hood and could hear a faint ‘hissing’ up under the top motor area (under plastic cover). I looked and never could find it. An no coolant anywhere. Just a hiss and smell of coolant. Exhaust is clear.
One other thing. This AM it finally got hot (blowing heat from vents) after 30 min. But when I parked it, same coolant smell and faint hissing from top motor area. Any clues?
 

Jeepwalker

Senior Member
Joined
Sep 8, 2017
Posts
3,137
Reaction score
3,330
Location
WI
Ram Year
2012 Reg Cab, 4x4
Engine
5.7 Hemi
By top 'motor area' ...are you referring to the engine, or blower motor? I assume engine. First make sure the engine is operating at it's rated temperature. I had a diesel that was running at 160 and the difference in heat output in the cabin between 160 and 185 was enormous. Like night and day. There could be a cooling issue to iron out (T-stat or another).

Well, track down that hissing area. If your defrost was on prior to shutting the vehicle off, it could be the A/C pressures equalizing out and mimicking the sound of leaking antifreeze ...because usually A/C comes on when the defrost is on. Or you could have a leak to track down. Is there a 'film' on the inside of your windshield? I mean the possibility of a heater core leak? Or 'girgling' (air bubbles) inside the heater core after you start the vehicle in the morning? That could point to a heater core leak. Even if your truck's heater core is leaking it should still provide heat, unless it's plugged. If they used tap water after replacing the engine's, yeah, that helps create mineralization inside the tiny passages of the heater core vanes. A guy should use filtered/RO water only (ideally). A plugged heater core can also cause a no-heat situation. Just because the hoses are warm doesn't mean you have proper flow through the heater core. The outside passages could be open, and the middle ones plugged.

If you knew someone who had a 'good' scanner, it would be real helpful to get into the HVAC control module and check for HVAC codes. Then perform an HVAC doors sweep test to test the blend door motors and full range actuation. During normal operation, the blend doors cycle and the computer notes when they reach full open and full closed ...so the computer know's the position of the blend doors (ie 30% or 72%). Motors can fail, and so can the hinges of some doors ...or where the motor connects to the door itself. Also, an outside air blend door or motor (to the cabin or the hvac box) failed (or the hinge busted), the heater can still provide heat, but not enough to overcome very cold 'fresh' outside air on a cold day. In other words there 'could' be more cold air entering the cabin entering the cabin than the heater can overcome (making it 'feel' cold inside). Or, if it was like our Jeep when we got it (used), it had multiple blend door issues the previous owner had not addressed ...and was a mess till we got it sorted out. Some of these blend door issues I've outlined may vary depend on the model truck you have (basic or dual-zone hvac). The dual-zone and more complex units tend to have more possible fail points.

Another thing you could do if you suspect a heater core leak, is pry up your pass door's sill plate and put your hand under the carpet (or matt) and feel for wetness under there. That's a pretty good sign of a heater core leak.
 
Last edited:

indept

Senior Member
Joined
Sep 10, 2017
Posts
3,213
Reaction score
4,740
Location
South Jersey
Ram Year
2017
Engine
Hemi 5.7L
The fact that you did get heat points to a blend door. A heater core blockage won't come & go. As for the smell, how is the antifreeze level? You can get fluorescent dye at a parts store and add some to the radiator, remove a little antifreeze from radiator to make room ( don't put it in the overflow tank). Drive it a while after engine reaches temp. Any leak will glow under a black light.
 
OP
OP
R

Ryan Poulos

Member
Joined
Jul 22, 2019
Posts
71
Reaction score
11
Location
Dallas
Ram Year
2007
Engine
5.7
By top 'motor area' ...are you referring to the engine, or blower motor? I assume engine. First make sure the engine is operating at it's rated temperature. I had a diesel that was running at 160 and the difference in heat output in the cabin between 160 and 185 was enormous. Like night and day. There could be a cooling issue to iron out (T-stat or another).

Well, track down that hissing area. If your defrost was on prior to shutting the vehicle off, it could be the A/C pressures equalizing out and mimicking the sound of leaking antifreeze ...because usually A/C comes on when the defrost is on. Or you could have a leak to track down. Is there a 'film' on the inside of your windshield? I mean the possibility of a heater core leak? Or 'girgling' (air bubbles) inside the heater core after you start the vehicle in the morning? That could point to a heater core leak. Even if your truck's heater core is leaking it should still provide heat, unless it's plugged. If they used tap water after replacing the engine's, yeah, that helps create mineralization inside the tiny passages of the heater core vanes. A guy should use filtered/RO water only (ideally). A plugged heater core can also cause a no-heat situation. Just because the hoses are warm doesn't mean you have proper flow through the heater core. The outside passages could be open, and the middle ones plugged.

If you knew someone who had a 'good' scanner, it would be real helpful to get into the HVAC control module and check for HVAC codes. Then perform an HVAC doors sweep test to test the blend door motors and full range actuation. During normal operation, the blend doors cycle and the computer notes when they reach full open and full closed ...so the computer know's the position of the blend doors (ie 30% or 72%). Motors can fail, and so can the hinges of some doors ...or where the motor connects to the door itself. Also, an outside air blend door or motor (to the cabin or the hvac box) failed (or the hinge busted), the heater can still provide heat, but not enough to overcome very cold 'fresh' outside air on a cold day. In other words there 'could' be more cold air entering the cabin entering the cabin than the heater can overcome (making it 'feel' cold inside). Or, if it was like our Jeep when we got it (used), it had multiple blend door issues the previous owner had not addressed ...and was a mess till we got it sorted out. Some of these blend door issues I've outlined may vary depend on the model truck you have (basic or dual-zone hvac). The dual-zone and more complex units tend to have more possible fail points.

Another thing you could do if you suspect a heater core leak, is pry up your pass door's sill plate and put your hand under the carpet (or matt) and feel for wetness under there. That's a pretty good sign of a heater core leak.
Thank you. You gave me a lot to cover. Im getting into it later today.
My truck also got hot today. I was idling in my car waiting to pick up my kid and it pegged the temp gauge. Nothing leaking. Still hissing. I will find the hiss and reprt back. Thank you for all your input here.
 
OP
OP
R

Ryan Poulos

Member
Joined
Jul 22, 2019
Posts
71
Reaction score
11
Location
Dallas
Ram Year
2007
Engine
5.7
By top 'motor area' ...are you referring to the engine, or blower motor? I assume engine. First make sure the engine is operating at it's rated temperature. I had a diesel that was running at 160 and the difference in heat output in the cabin between 160 and 185 was enormous. Like night and day. There could be a cooling issue to iron out (T-stat or another).

Well, track down that hissing area. If your defrost was on prior to shutting the vehicle off, it could be the A/C pressures equalizing out and mimicking the sound of leaking antifreeze ...because usually A/C comes on when the defrost is on. Or you could have a leak to track down. Is there a 'film' on the inside of your windshield? I mean the possibility of a heater core leak? Or 'girgling' (air bubbles) inside the heater core after you start the vehicle in the morning? That could point to a heater core leak. Even if your truck's heater core is leaking it should still provide heat, unless it's plugged. If they used tap water after replacing the engine's, yeah, that helps create mineralization inside the tiny passages of the heater core vanes. A guy should use filtered/RO water only (ideally). A plugged heater core can also cause a no-heat situation. Just because the hoses are warm doesn't mean you have proper flow through the heater core. The outside passages could be open, and the middle ones plugged.

If you knew someone who had a 'good' scanner, it would be real helpful to get into the HVAC control module and check for HVAC codes. Then perform an HVAC doors sweep test to test the blend door motors and full range actuation. During normal operation, the blend doors cycle and the computer notes when they reach full open and full closed ...so the computer know's the position of the blend doors (ie 30% or 72%). Motors can fail, and so can the hinges of some doors ...or where the motor connects to the door itself. Also, an outside air blend door or motor (to the cabin or the hvac box) failed (or the hinge busted), the heater can still provide heat, but not enough to overcome very cold 'fresh' outside air on a cold day. In other words there 'could' be more cold air entering the cabin entering the cabin than the heater can overcome (making it 'feel' cold inside). Or, if it was like our Jeep when we got it (used), it had multiple blend door issues the previous owner had not addressed ...and was a mess till we got it sorted out. Some of these blend door issues I've outlined may vary depend on the model truck you have (basic or dual-zone hvac). The dual-zone and more complex units tend to have more possible fail points.

Another thing you could do if you suspect a heater core leak, is pry up your pass door's sill plate and put your hand under the carpet (or matt) and feel for wetness under there. That's a pretty good sign of a heater core leak.
I took your advice. Thanks. As a hunch I did the thermostat assembly.
It now does not overheat. And hissing gone. I think what I was hearing was the overflow tank hose.
Im staying around 215-219 degrees.

Also pulled out the glovebox.
My recirc door us up when on heat, and down when on AC. Could it be a clogged heater core even with both hoses hot under hood?
 

Attachments

  • 5A2E01F9-AE83-443D-8A71-32921FBD9CBA.jpeg
    5A2E01F9-AE83-443D-8A71-32921FBD9CBA.jpeg
    135.1 KB · Views: 4
Last edited:
OP
OP
R

Ryan Poulos

Member
Joined
Jul 22, 2019
Posts
71
Reaction score
11
Location
Dallas
Ram Year
2007
Engine
5.7
The fact that you did get heat points to a blend door. A heater core blockage won't come & go. As for the smell, how is the antifreeze level? You can get fluorescent dye at a parts store and add some to the radiator, remove a little antifreeze from radiator to make room ( don't put it in the overflow tank). Drive it a while after engine reaches temp. Any leak will glow under a black light.
Thank you. I cant find a leak anywhere. I was a little low. Im going to drive it today after I did the thermostat. I figured for $100 Id try it. Its now not overheating in my driveway running 28 minutes. But I’ll drive it for a bit.
Heater is still not working and the actuator is working properly.
 

Elvira

Senior Member
Joined
Aug 11, 2018
Posts
443
Reaction score
827
Location
Somewhere
I would say the blend door is non operating. I have fixed them before where they have broken off a little tab that fastens to the actuator leaver. In a pinch, this time of year...just prop open with clothes pin or what ever. You can order the door or part as needed when you decide to fix. This is an educated guess without seeing it, but a good probability.
 
Last edited:

GTyankee

Senior Member
Supporting Member
Military
Joined
Nov 2, 2020
Posts
10,061
Reaction score
12,607
Location
El Cajon Calif. 92021
Ram Year
2016
Engine
3.0 ecodiesel
First a friendly note:

A motor is powered with electricity
An engine is powered by anything else, ( unless you live in England )
-------------------------------------------------------------------------------
In your Climate Control Unit
You have 4 doors, each run by actuators, actuators are usually interchangeable, ( a Mega Cab has 5 actuators )

Behind the upper glove compartment, there is a Recirculation Door
Below it & slightly to the left of the Fan, there is a Blend Door
Directly in back of the Climate Control Panel, there is a Mode 1 door
Just above where your right ankle would normally rest when driving, there is a Mode 2 door

------------------------------------------------------------------

I would try moving the knobs on the control panel to see what is actually working. A/C, Low, medium, High speeds, heat or cold to the floor, heat or cold to the vents, cold to the defrost.

I would determine which heater hose carries the water into the heater & which is the return line.

Then watch a Youtube video on how to backflush the heater core in the cab, back flushing pushes any debris out the inlet hose, do Not use High Pressure
----------------------------------------------------

Each actuator can be disconnected from the housing ( 2 screws ), & you can watch it cycle once you connect it back into the electrical socket

also once the actuator is detached, you can gently move the metal rod that moves the different doors, you may hear the door as it fully opens or closes.

If you decide to remove the Climate Control Box from under the dash board.
The Mopar Actuators are the quality unit
The different doors, you would want to stay away from the Mopar doors
Many people use the Dorman replacements
Personally, i would spend a bit more & get the ones from https://www.blenddoorusa.com/
If i planned on long term ownership

Grab a beverage of your choice, put your feet up & hopefully learn about your climate control system

 
OP
OP
R

Ryan Poulos

Member
Joined
Jul 22, 2019
Posts
71
Reaction score
11
Location
Dallas
Ram Year
2007
Engine
5.7
If an intake gasket were leaking would I hear the hissing noise? After 3 hours of driving it finally is getting hot again. And hissing is back. Sound front of motor and internal. Not leaking inside or outside. Must be burning internal. No smoke from pipe it smell from pipe. Any ideas???
 

cancunlsp

Junior Member
Joined
Nov 26, 2018
Posts
26
Reaction score
20
Location
Va
Ram Year
2016
Engine
5.7 Hemi
I had this same problem last winter. Mine was simple (thank goodness), something had gotten into the blower and had jammed it so it wasnt turning or blowing any air so all the hot air was just sitting in the dash
 

smiley

Senior Member
Supporting Member
Joined
Apr 18, 2011
Posts
6,622
Reaction score
2,955
Location
Minot, ND
Ram Year
2014 Ram 2500 Crew
Engine
6.7L Cummins
First a friendly note:

A motor is powered with electricity
An engine is powered by anything else, ( unless you live in England )
-------------------------------------------------------------------------------
In your Climate Control Unit
You have 4 doors, each run by actuators, actuators are usually interchangeable, ( a Mega Cab has 5 actuators )

Behind the upper glove compartment, there is a Recirculation Door
Below it & slightly to the left of the Fan, there is a Blend Door
Directly in back of the Climate Control Panel, there is a Mode 1 door
Just above where your right ankle would normally rest when driving, there is a Mode 2 door

------------------------------------------------------------------

I would try moving the knobs on the control panel to see what is actually working. A/C, Low, medium, High speeds, heat or cold to the floor, heat or cold to the vents, cold to the defrost.

I would determine which heater hose carries the water into the heater & which is the return line.

Then watch a Youtube video on how to backflush the heater core in the cab, back flushing pushes any debris out the inlet hose, do Not use High Pressure
----------------------------------------------------

Each actuator can be disconnected from the housing ( 2 screws ), & you can watch it cycle once you connect it back into the electrical socket

also once the actuator is detached, you can gently move the metal rod that moves the different doors, you may hear the door as it fully opens or closes.

If you decide to remove the Climate Control Box from under the dash board.
The Mopar Actuators are the quality unit
The different doors, you would want to stay away from the Mopar doors
Many people use the Dorman replacements
Personally, i would spend a bit more & get the ones from https://www.blenddoorusa.com/
If i planned on long term ownership

Grab a beverage of your choice, put your feet up & hopefully learn about your climate control system

Why do they call it motor oil then? I have heard this before when someone said motor vs engine. I didn’t really get it.
 

GTyankee

Senior Member
Supporting Member
Military
Joined
Nov 2, 2020
Posts
10,061
Reaction score
12,607
Location
El Cajon Calif. 92021
Ram Year
2016
Engine
3.0 ecodiesel
Smiley
The only thing that i found is still confusing
Just like the rest of the World uses the Metric System & the USA uses the SAE system, In a decade or 2, the whole world will be Metric.
We call the cover over an engine a Hood, many other countries call it a Bonnet

England & many other countries call a combustion engine a Motor
We call it an engine

WHAT IS THE DIFFERENCE BETWEEN ENGINE OIL AND MOTOR OIL?
There is no difference. Just like how both lawn and yard mean the same thing; both engine oil and motor oil are valid ways of talking about the oil that lubricates your engine.

Another thing, some people have Yard Sales, Tag Sales, Flea Market, Garage Sales, rummage sale. The name seems to change with the part of the country that it is held in.
 
Last edited:
Top