Heater hose routing

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Lonewolfwd

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I have an 03 Ram 1500 with 4.7 and I need to know the correct routing for the heater hoses. My problem is I had no heat when it got cold so I just replaced the thermostat and went to purge the system like I'm supposed to but when the engine is cold and I go to fill the radiator all my coolant wants to come out the bleed screw. I have the reservoir/overflow tank and that hose is connected to the top of the heater core and the top side of the water pump. Do I have them hooked up wrong?

I have a complete new engine, radiator, heater core, hoses and now thermostat but I know something is wrong cause coolant shouldn't be coming out the bleeder when the engine is cold and I try to fill the radiator.
 
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Lonewolfwd

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Finally found a diagram of the hose routing and I was wrong on my hoses as I looked at them wrong, mine was on there correct. I finally had to pull the heater hose from the heater core for it purge the air out no idea why but that was the only way I could get it to purge.

My next question on this p.o.s. is why it has never had very hot heat. The truck since I have owned it for 3+ years now has always had luke warm heat, is that common with these 4.7s or what? I thought the heater core might have been plugged up so that is why when I put the new engine in along with a new radiator I had just put in a new heater core at the same time but that didn't fix the problem.
 

Daw14

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Check your thermostat may have a 160* or 180*
 
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Lonewolfwd

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The door in my box is working correctly, checked it when I replaced the heater core and I put in a 195* thermostat. My temp gauge runs just shy of the middle mark and the coolant is so hot you can't put your finger in it so I know it's up to temp. My fan seems like it doesn't blow like it should so maybe that is my problem. When I change fan speeds I can the fan speed up or slow down but the air movement doesn't change very much.

I seen some place where they said some fans are wire backwards and blow the wrong direction, is that true?
 

srv1

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is there any blockage on top of the blower,maybe the recirc. door?happened to me,i could hear the fan speed up but air speed stayed the same out of vents.recirc. door fell out and was laying on the blower.
 
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Lonewolfwd

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I have been trying to get this P.O.S. 4.7 to purge the air out of the heater core and I'm at the point of being ready to use some dynamite on it. I just put another new water pump and fan clutch on it so at this point everything is new. I go through the full process to purge it but for some reason it will not purge the heater core. The truck never over heats or anything and all the hoses are hot except the top heater hose it is always cold. To me it seems like it is not pushing my coolant through the heater core and I have no idea why.
 

kevkev

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I have a 180 thermostat so mine doesnt really get hot either. When bleeding your cooling system, run your vehicle with the nose pointed upwards on a hill. The air will work its way out. I know, it sounds stupid.
 

EdGs

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On my 02 4.7L, the door was lying on top of the blower, it would sometimes have next to no air flow.

Unscew your blower motor and reach up in there, door might be laying there.

As far as heater core goes, they do get plugged up, especially when the previous owner puts stop leak in it to fix a coolant leak. Mine was plugged up pretty good, as I found out replacing the head gaskets. I had to flush it with a hose, going very easy on the pressure, but I got it clear thankfully. I even think I filled the core with the top hose disconnected, then reconnected it.

The previous post was spot on about the nose pointing up. The heater core is higher than the rest of the system I think.
 
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Lonewolfwd

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My complete cooling system is new along with the motor so I know it's not plugged up any place as I have flushed the whole system a couple of weeks ago just to make sure.

I never thought about filling the heater core with the top hose off so I might try that today and see if that does the trick. I usually pull the truck up on my ramps when I bleed it which puts the front end up almost 3 feet.

Will see what happens and go from there. I'm almost to the point of telling Dodge where to stick the truck and find something different.
 

EdGs

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Check your fan too, on mine the recirc door was laying on top of the blower.

Sometimes it would blow decent, then at times it wouldn't. I unscrewed the blower, stuck my hand in the hole, and there was the recirc door.

Don't give up.
 
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Lonewolfwd

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I finally got some heat in my truck but not a lot. I did pull my fan and the door was broke and laying on top of my fan so I took it out and now it blows like it should but still fighting with getting heat.

It was 19 degrees yesterday morning and I can get just enuf heat out of it to keep it around 40 degrees in the truck. The 3 vents on the passenger side will blow some heat but the 2 vents on the drivers side blow cold air like I have the A/C on. My heater hoses are hot now so I know the coolant is flowing through the heater core.
 

EdGs

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I think I replaced the broken recirc door and motor.

Sorry, I forget how I actually did it, just remember it was kind of a ***** to do. I believe the recirc door motor sits sideways. Can't remember if I had to remove the radio or not.


Hang in there.
 
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Lonewolfwd

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I'll do some more looking and see what I get into and go from there. This is the first Ram I have ever had any kind of problems with like this and I'm getting tired of fighting with it.
 

Funkadelic

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I'm having the exact same issue with my 03 with the 4.7L. Get warm heat but not hot and have replaced broken blend doors, heater core and thermostat. Tried purging system of air a few times now and no difference. Sorry I don't have any answers, just wanted to let you know I'm in the same boat.
 

Orange whip

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Hi does Anybody know the orientation for a 2005 4.7 ram 1500 hose connections from firewall down to the thermostat what hose goes on top and what hose at the bottom 2 connections down by thermostat? This motor has the thermostat housing at bottom. One has a anti freeze in it the other does not.
 

GTyankee

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Orange Whip, if you could would you start a new thread of your own
This thread is from December 2020

I will tell you that you should take your water hose or Compressed air
hold the water or air hose & stick it into your hoses that come out of the firewall at low pressure, the old water will come out of the other hose, catch the old water in a bucket.
After you do that to one hose, do it to the other hose that comes out of the firewall
That will eliminate any chance of blockage in the Climate Control box inside of the cab
 
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