water dripping under dash

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Rustycowl69

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01 Ram 3500 4wd v10 206K miles. Ok, one of my worst fears. Yesterday started up truck for first time in a couple months. I turn on the fan to high, and defrost. My wife says, "what's that?" Damn! There are a couple of fresh rivulets of water on the floor mat, right top side of tunnel. This accompanied by an instantly fogged winshield. I'm thinking there went the heater core. This is probably my worst fear, replacing the heater core. How bad is it going to be. Any good tips. A blow-by-blow would be most helpful. The last time I tried this I broke the heater box trying to remove it from my 79 300.
 

crash68

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if it's not green(or what color the anti-freeze is) then it's not your heater core. Check the condensate drain for the AC, it's probably plugged. The AC runs when in Defrost.
 
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Rustycowl69

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a/c stopped working about a year ago. what I mean is the compressor clutch stopped working about a year ago.
 
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dapepper9

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Can you smell coolant? Kind of a maple syrup/celery smell (sounds weird but makes sense if you smell it)
 

dudeman2009

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The heater core is actually pretty easy compared to the fords and post 2003 Chevys.
6 bolts on the dash, pull it aside, 6 bolts on the HVAC box, loosen the A/C accumulator and pull the Hvac box out a bit, cut the heater core tubes with a hacksaw, pull them through the firewall and remove them from the rubber hoses in the engine bay (way easier than fighting with them in the firewall). Then just tilt the HVAC box out towards the bed and slide the new one in. Run the heater lines back through the firewall and hook it up inside the cab. Took me about 4 hours to figure it all out myself.

I'll see if I can find a video that I was dumb enough not to look for before trying to replace my heater core. I could probably do it in an hour and a half now.
 
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Rustycowl69

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I don't want to replace a brass/ copper heater core with a POS O'Reilly aluminum junk core, because I don't want to do this again. Is there a quality aftermarket heater core out there, or do I have to go thru stealership?
 

dudeman2009

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I don't want to replace a brass/ copper heater core with a POS O'Reilly aluminum junk core, because I don't want to do this again. Is there a quality aftermarket heater core out there, or do I have to go thru stealership?

As far as I know, even the dealer uses aluminium cores. The aluminium ones really don't have problems, like the aluminium radiators. Sure over a long period of time they will clog, but aluminium doesn't corrode very much at all in either air or water. Copper on the other hand corrodes just sitting in air, and water doesn't help much to stop it, thats why they mix brass in, to reduce the amount of oxygen corrosion. But it cant be all brass or it would have other issues. Aluminium is the way to go, it doesnt transfer heat as well as copper/brass, but it will work just fine. I have a 180*T-stat and I get pretty hot air. When I put the cardboard in front of the radiator and the coolant steadied out at 200* I had amazing head even with the A/C going full tilt.

There is nothing wrong with the aluminium ones, but if you are worried, just don't get the movable tube version, get the solid or rubber hose version.
 

Marksman

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Changing the heater core really isn't that bad of a job. When I replaced my dash, I decided to go ahead and change both the heater core and the A/C evaporator core while I was in there. I would suggest doing both of these because they're dirt cheap. I think I got both for around $60 total on rockauto. I've heard that both are prone to leaking and I didn't want to have to go in there again. The heater core I received was aluminum.

Getting the hoses off of the heater core was the hardest part of the job. The plenum on the V10 is right in front of where the hoses attach and I couldn't even get back there to get the damn clamps off because they're the type you have to use pliers on. I wound up just leaving them attached until I had the heater box loose and pulled the hoses/clamps through the firewall into the cab and detached them then. I did the same for the reassembly. I should've changed all of that while I had the engine out. Oh well.

If I remember correctly, you:
-drop the column
- remove the screws inside at the base of the windshield
- Remove the bolts holding the dash to either side of the cab, there are two beside the emergency brake foot activated thing, and one (Maybe 2, cant remember) bolts in the same location on the passenger side of the cab.
-In the center of the dash, below the cup holders where the dash meets the floor (if you have an automatic) there is a plastic cover with 2 screws holding it on. Remove that, I think there are a couple of bolts under it.
-I think you might have to remove the air bag from the passenger side. Make sure you've had the battery cable off for at least an hour before unplugging it.

After that, the dash should pull back on the passenger side. I took a ratchet strap and hooked it to the dash and to the grab handle to hold it out of the way.

To get the heater box out, there are I think 2 10mm nuts holding it on from the inside, and I believe 4 holding it in on the outside. You'll have to remove the computer to get to some of them. One is behind the plenum so it was a PITA, but I managed to get it off. Not sure if I put it back on when I reassembled though.

Including replacing the dashboard, I think it took me around 3 hours or maybe a bit longer. It certainly didn't take near as long as I had expected.
 

dudeman2009

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Marksman is pretty spot on, except you DO NOT reed to touch the airbags, you can work around it.

There are four on the steering column
The screws along the windshield, six I think.
The two plastic kick panels on the outside of either footwell hide one large nut on each side
In the center under the cupholders behind the plastic cover there are two bolts, one on either side.

Then start pulling the dash back on the passenger side, this is a long process as there is a large wiring connector in the center on the floor that needs to be disconnected, as well as some connectors behind the passenger airbag (you can get to those by just reaching around as you pull it back. you will be going from one side to the other to schooch it out inch by inch until it is comfortable to work behind.

Marksman has a great idea, something that I only figured out halfway through, take a ratchet strap from the dash and hook it to the rear door roof latch if you have the suicide doors, or run it out and hook it onto the lip of the bed.

There are two nuts on the inside behind the passenger airbag, there are four in the engine bay. One is behind the PCM, another is behind the A/C accumulator, the other two are on the firewall. On the V8's there is a 5th nut in the very center behind the intake, do not remove that, that is for the air plumbing, that can stay.
 

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Marksman

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Thanks for clearing the air bag thing up. I had to pull it to install the new dash.

I'll have to say, I don't recall unhooking a large electrical connector at the center of the dash, just the few for the airbag, blower and blower motor resistor.

So you're saying I didn't have to take that nut behind the intake off? Damn.
 
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