Another dual climate heater issue

[JaKaL3482]

This one’s gonna be a long one, stay with me..

So I’ve used the search and couldn’t find what I was looking for. Finally decided to join so I can ask what I really need to know. Brand new to this site.

The truck
2016 ram bighorn with all options besides leather and sunroof.

142k miles
Full delete
Raceme tuner
6 inch lift
37 inch tires
Factory 4 link front and rear

The issue

Heater absolutely sucks

What I’ve done

*Flushed, and back flushed heater core (great flow in and out, little bit of gunk but not terrible.)
*Flushed engine completely and refilled after putting in new coolant resivoir
*Burped the air out of the system
*All hoses roughly same temp when warmed up
*Added an air blocker between intercooler and radiator with 5” hole in center for fan
*New Cummins tstat

This truck has dual climate control, and both sides seem to be doing the same temps. I’ve only had time to check recirc and the blend door actuator behind the glovebox. Both work fine from what I can tell. I pulled the one behind the glovebox off and it moved how it should. Flipped the door from the outside and it went full cycle end to end. I really don’t want to pull the dash to find out it’s something easy I’m overlooking. One time I moved the temp down and back up and it worked until I touched it again. But I can’t get it to do it again.

I’m thinking my blend doors are either broken inside or partially blocked with something, or my heater core is dirty on the outside. But that wouldn’t explain it working once. Seems to be more something electrical

I did a reset on my uconnect and it didn’t change anything.

It seems like with. It sides having the same temps that it’s not the right/left blend doors. But I haven’t pulled the fan and ran an endoscope up there to see yet. Ran out of daylight.

What the actual F am I missing here. I can’t afford to loose more hair…

 

[nlambert182]

Heater core. Mine did the same thing until I replaced it last week. Everything works perfectly now. My core looked clear too, but it wasn't. Backflushing only got me heat for a few days. The last attempt got me heat once. That was it.

 

[SitKneelBend]

This one’s gonna be a long one, stay with me..

So I’ve used the search and couldn’t find what I was looking for. Finally decided to join so I can ask what I really need to know. Brand new to this site.

The truck
2016 ram bighorn with all options besides leather and sunroof.

142k miles
Full delete
Raceme tuner
6 inch lift
37 inch tires
Factory 4 link front and rear

The issue

Heater absolutely sucks

What I’ve done

*Flushed, and back flushed heater core (great flow in and out, little bit of gunk but not terrible.)
*Flushed engine completely and refilled after putting in new coolant resivoir
*Burped the air out of the system
*All hoses roughly same temp when warmed up
*Added an air blocker between intercooler and radiator with 5” hole in center for fan
*New Cummins tstat

This truck has dual climate control, and both sides seem to be doing the same temps. I’ve only had time to check recirc and the blend door actuator behind the glovebox. Both work fine from what I can tell. I pulled the one behind the glovebox off and it moved how it should. Flipped the door from the outside and it went full cycle end to end. I really don’t want to pull the dash to find out it’s something easy I’m overlooking. One time I moved the temp down and back up and it worked until I touched it again. But I can’t get it to do it again.

I’m thinking my blend doors are either broken inside or partially blocked with something, or my heater core is dirty on the outside. But that wouldn’t explain it working once. Seems to be more something electrical

I did a reset on my uconnect and it didn’t change anything.

It seems like with. It sides having the same temps that it’s not the right/left blend doors. But I haven’t pulled the fan and ran an endoscope up there to see yet. Ran out of daylight.

What the actual F am I missing here. I can’t afford to loose more hair…

You could try blue devil directly in the heater core, let it set for 15 minutes or so. Then back flush with "some" pressure in bursts. You'll need to drain the core then plug one end and hold the other above core level to get the blue devil in.

Edit: might be worth checking the 3 way coolant bypass valve, I'm not sure if it's operation but I'm pretty sure the heater core feeds into it.

 

[JaKaL3482]

I would think if the heater core was shot the outgoing coolant pipe would be much colder. I did the blue devil thing. With bursts. And got a little gunk out. I’m leaning more towards the hc being the problem. The only thing that gets me is when I moved the temp it got real hot, like the flap was jammed. I think I’ll just bite the bullet and swap it. Fml

 

[GTyankee]

First of all ,
Does your HVAC Blower change speeds when you work the HVAC Controls ?

When you removed the Glove Compartment Door

Did you watch the Actuator located just to the Left of the Fan, as you worked the HVAC Controls ?

Did you see the Actuator move the White Lever up & down ?


for Mode Doors Actuators behind the Radio Bezel
on a
Dual Zone

DODGE RAM 1500-3500 BLEND DOOR ACTUATOR REPLACEMENT 2010-2012

This is for the door actuator https://www.amazon.ca/Dorman-604-005-Air-Door-Actuator/dp/B00CI6GGPM/ref=pd_ys_c_rfy_rp_m_289_1?_encoding=UTF8&pd_rd_i=B00CI6GG...

www.youtube.com

by the way, he used Dorman Actuators
They will fit
But they will not auto synchronize with the Controls like the Mopar actuators will

 

[nlambert182]

I would think if the heater core was shot the outgoing coolant pipe would be much colder. I did the blue devil thing. With bursts. And got a little gunk out. I’m leaning more towards the hc being the problem. The only thing that gets me is when I moved the temp it got real hot, like the flap was jammed. I think I’ll just bite the bullet and swap it. Fml

Not necessarily. Both my pipes were similar enough in temperature that you couldn't tell by feel. There's a really strong chance that the core is still bad. I'd start there before dumping a ton of money into electronics.

 

[SitKneelBend]

I would think if the heater core was shot the outgoing coolant pipe would be much colder. I did the blue devil thing. With bursts. And got a little gunk out. I’m leaning more towards the hc being the problem. The only thing that gets me is when I moved the temp it got real hot, like the flap was jammed. I think I’ll just bite the bullet and swap it. Fml

You may be right, the heater core has a tendency to collect lots of impurities in the coolant. I only say that I would flush it again (since it worked the first time) because it is a much simpler task. One thing to be mindful of is to only use the correct MOPAR coolant (the purple stuff). If at any time another coolant was mixed with it it will cause the coolant to coagulate into orange looking globs. It may be prudent to flush the coolant too since you are going to do the heater core anyway.

 

[JaKaL3482]

First of all ,
Does your HVAC Blower change speeds when you work the HVAC Controls ?

When you removed the Glove Compartment Door

Did you watch the Actuator located just to the Left of the Fan, as you worked the HVAC Controls ?

Did you see the Actuator move the White Lever up & down ?


for Mode Doors Actuators behind the Radio Bezel
on a
Dual Zone

DODGE RAM 1500-3500 BLEND DOOR ACTUATOR REPLACEMENT 2010-2012

This is for the door actuator https://www.amazon.ca/Dorman-604-005-Air-Door-Actuator/dp/B00CI6GGPM/ref=pd_ys_c_rfy_rp_m_289_1?_encoding=UTF8&pd_rd_i=B00CI6GG...

www.youtube.com

by the way, he used Dorman Actuators
They will fit
But they will not auto synchronize with the Controls like the Mopar actuators will

Yea the blower changes speeds, the white arm does go up and down when I change temps. I pulled it off and moved it by hand to see if maybe it felt broken behind it. I heard an audible thud when I flipped it each way, put it back on and it worked the same as it did before. I can move it between zones as it should. The heat definitely feels hotter from the vents vs floor and defrost. Both sides blow out the same temps roughly.

 

[nlambert182]

If all of that is working, it's likely not an actuator problem. You may feel slightly warmer air from one set of vents over the other depending on how far the air has to travel. The further from the core, the cooler it will get.

 

[GTyankee]

Being as you have the Dual Zone System

I think that in one position, air should be going to the rear seats, right at the Drive Shaft Tunnel, either just to the sides of the tunnel or at the rear vents, just above the tunnel.
In that case, there is a chance that the air is going back there, instead of to the dash vents ????????????????

Part #20 carries AIR from the HVAC Floor Vent above the Drive Shaft Tunnel, back under the Floor Console or middle seat, to the vents at the people in the rear seats.
See part #14


.....................................................................................
No wonder this guy only has 35 followers
he should have slowed down, so that we can really see what is going on

4th Gen Ram HVAC Rebuild

Rebuilding and upgrading Ram HVAC box, replace heater core, convert to dual zone, convert to 7 speed fan control and upgrade blend doorsdual zone and 7 speed...

www.youtube.com

But he does show that if you want to change from a Single Zone system, to a dual zone system, it can be done

 

[JaKaL3482]

Being as you have the Dual Zone System

I think that in one position, air should be going to the rear seats, right at the Drive Shaft Tunnel, either just to the sides of the tunnel or at the rear vents, just above the tunnel.
In that case, there is a chance that the air is going back there, instead of to the dash vents ????????????????

Part #20 carries AIR from the HVAC Floor Vent above the Drive Shaft Tunnel, back under the Floor Console or middle seat, to the vents at the people in the rear seats.
See part #14

View attachment 555471
.....................................................................................
No wonder this guy only has 35 followers
he should have slowed down, so that we can really see what is going on

4th Gen Ram HVAC Rebuild

Rebuilding and upgrading Ram HVAC box, replace heater core, convert to dual zone, convert to 7 speed fan control and upgrade blend doorsdual zone and 7 speed...

www.youtube.com

But he does show that if you want to change from a Single Zone system, to a dual zone system, it can be done

The rear vents work when the front vents work, when it’s on defrost or floor they are off. The air pressure coming out is good, just colder than it should be.

Being as you have the Dual Zone System

I think that in one position, air should be going to the rear seats, right at the Drive Shaft Tunnel, either just to the sides of the tunnel or at the rear vents, just above the tunnel.
In that case, there is a chance that the air is going back there, instead of to the dash vents ????????????????

Part #20 carries AIR from the HVAC Floor Vent above the Drive Shaft Tunnel, back under the Floor Console or middle seat, to the vents at the people in the rear seats.
See part #14

View attachment 555471
.....................................................................................
No wonder this guy only has 35 followers
he should have slowed down, so that we can really see what is going on

4th Gen Ram HVAC Rebuild

Rebuilding and upgrading Ram HVAC box, replace heater core, convert to dual zone, convert to 7 speed fan control and upgrade blend doorsdual zone and 7 speed...

www.youtube.com

But he does show that if you want to change from a Single Zone system, to a dual zone system, it can be done

all the vents seem to work and blow as intended. It’s just a temperature issue. When the dash vents are on, the rear vents are too. But that’s the only setting I’ve seen them work.

 

[JaKaL3482]

Is it possible to pull the blower and scope up in there and see the heater core? Looking at the box it seems like it’s possible. But then maybe I can see if I have a broken door or something.

 

[JaKaL3482]

Also wondering if since it doesn’t have the filter if my condenser is just full of junk and the fan can’t blow through to the heater core. One day when I’m not running on 2 hours of sleep I will pull that fan out and see if I can see anything.

 

[nlambert182]

If you're getting air, it's blowing through the core. The problem is likely that the core isn't heating up enough to give you warm air. My honest opinion and take it for what it's worth, you're going through a whole lot of effort only to end up coming back to the core.

 

[JaKaL3482]

If you're getting air, it's blowing through the core. The problem is likely that the core isn't heating up enough to give you warm air. My honest opinion and take it for what it's worth, you're going through a whole lot of effort only to end up coming back to the core.

I think you’re right. Just hoping you’re not. Lol.

 

[nlambert182]

Easier to accept it now.

It only hurts once.

 

[JaKaL3482]

Heard that. The couple things that bother me that I can’t make it make sense are. I’ve messed with the temp control and got it to work once before I flushed anything, and the heater hoses are the same temperature in and out of the heater core. I just don’t get that. Is there a way to pop a hole in the box and shove an endoscope in just to see if that rear door is the issue. Hasn’t come out either way but at least the parts could be here when got it out.

 

[SitKneelBend]

Is it possible to pull the blower and scope up in there and see the heater core? Looking at the box it seems like it’s possible. But then maybe I can see if I have a broken door or something.

If you're wanting to scope it, I've found this cheap scope pretty good at inspecting hard to reach places...

https://www.amazon.com/gp/product/B07PBF6DX5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[JaKaL3482]

I have a stand alone one. I had that one for my phone but it kept disconnecting. That was a while ago I sure they are better now. I guess I could just tap in behind the doors and watch them move. I don’t know if there’s a divider between them or not.

Never thought I’d be the guy to buy a stripped hvac box and P1mp my ride with it.

It does seem like the heat is hotter on lower fan speeds.

 

[nlambert182]

Yes and it will be because the air speed is moving slower, so the luke warm air doesn't cool down as quickly.