my 97 ram 1500 does not blow out hot air, sometimes will get warm but thats it. will change from vent, to defrost etc, it's just cold air. it feel s like both heater hoses are heating up about the same rate, radiator full of antifreeze, any suggestions. thanks

 

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Burp the cooling system. Chances are, you have an air pocket in the heater core. (I have been fighting this for far too long now...)

 

I'm not quite sure what goes on with these Dodges but it's not specific to the Ram. I have both a 1998 Durango, and a 1998 Ram, and a friend's 1999 Ram that I work on a lot.

My Durango has had two heater cores put in it. It's been flushed with a solvent and the mixture has been played with favoring both water and coolant. I have drilled tiny holes in the T-stat to help with air pockets, and I have put the Durango on a near 45 degree incline and ran and revved until I couldn't hear air in the heater core. The core tubes that I can touch are super hot to the touch. The hoses inside the engine bay are hot to the touch, same for the radiator hose and radiator. I have verified the motor that controls the blend door is operating as it should and the blend door properly mixes the air. I get cold A/C in the summer so I know the path through the core and evap are not blocked with debris or grime. However, after all of that...which includes TWO core replacements...it barely gets warm enough to defrost the windshield.

My Ram, and my friend's Ram are in the same boat minus the core replacements. I have run through that entire list with both trucks and neither has any significant heat to speak of and I am really at a loss as to why. It just makes no sense.

My thinking is that I have hot fluid flow through the core. A garden hose flush through the hoses both ways indicates a great flow both ways. No clogs or leaks. Air flow from the vents is good so I believe air flow through the core and the evap are fine. The blend doors work so air should be diverted through the correct passage. The fluid is hot enough to heat up the tubes at the top of the core so what else could be wrong.

I have been fighting this fight for many years now as well, and I have just gotten used to driving around and being a little more cold than I used to be while in the cabin. Oh well.

 

My next trick is going to be to install one of the capped tee's from a flush kit, at the highest point of the heater hoses, and see if that doesn't help. (I have had the kit for a while now, just havent managed to get out there and DO IT. I hate the cold, and can't work outside for very long....... and no heat in the garage or barn yet.

 

that's a good idea. you could separate the T for a flush, or remove the screw on cap for an air vent.

my heat doesn't get HOT anymore like it used to. (come to think of it neither does the wife). the blend door works to vary from cold to warm, but it just won't get hot. both heater hoses are hot (180). maybe time for a chemical coolant flush.

 

Mine heats well with 180 stat. Gotta be air in system, restricted flow in core, or scale interfering with heat transfer if heater doo and airflow is good.

 

both hoses are almost equal, but not so hot you can't touch them, how do you get to the blend door? i want to make sure it is opening and closing all the way before i do anything else. my temp gauge show it warming up to 200 then when thermostat opens drops to 180 and is pretty steady there, antifreeze looks clean. i don't hear a "gurgling" sound like alot of people hear with air in the system.

 

There are a couple things you can do from the cabin...but none of them is access the blend door itself. This can only be accessed by removing the dash assembly...not just the cap, and cracking it like a shell to access the core, evap, ducts, and door.

From the cabin, lean in and lay on the passenger side floor board and you can see the big black air box. There is a place where you can actually touch the top arches of the copper tubes that make up the inlet and outlet of the heater core. If the engine is hot and running, these should be super hot to the touch. Mine were.

Next, towards the bottom on the inward side, you'll see where the blend door motor is, and you can barely see a a bushing type of washer. Watch this part as you turn the temp from cold to hot. It'll start slowly turning and stop. Do this a few times after it starts and stops and make sure it's starting and stopping in the same places. The motor does not have physical stops at all...it uses resistance to stop the door which I think is stupid. LOL.

Once you have done this you have verified that the motor works, the bushing is not worn out, and the blend door is opening and closing. If the tubes are hot you have verified that the core is getting hot fluid from the engine. If both heater hoses are hot to the touch then hot coolant is flowing through the core. If you do a back flush using a garden hose and just the heater hoses, you can verify flow integrity, which I have done.

If the only thing left is the possibility that there is a scale build up I think chemical warfare is the last option. I was kind of thinking to disconnect both heater hoses, fill the core and hoses with a CLR type of solutions and let it sit for a few minutes, then flush and back flush.

I performed a chemical flush with the system together and running but the heat never got better so if there is a scale problem it's too tough for the Prestone type solvent to fix. I thought something stronger might be worth a try.

 

His is a 97, no motor for the blend door on his, it's cable operated. You can feel the axle on the bottom of the heater box, but, that's about it. Cable IS adjustable..... procedure is in the service manual, which you can download from the faq section here. (get the 96 version, don't have the 97....)