I am looking for some advice on a poor heat condition I have. I suspect the blend door but have been unable to find a schematic of the heat duct. The issue is this: Engine operating temp is 200 degrees, new waterpump, flushed radiator and heater core. Both hoses at heater core are hot. I hooked a hooked a hose up to one side of the heater core and check the amount of flow through the heater core. As fast as I could push it in it was coming out. I had the dash partially out and could operate the the blend door. The blend door felt and sounded like it was moving through the full range but I could not figure out how to see inside the duct where the a/c condenser, heater core, and blend door reside. How do I get that assembly apart? Do I have to take it out as unit with heater core and a/c lines disconnected or can I get the top half off somehow? I have a 96 RAM 1500 and the heat works great, the 1997 2500 bad heat and I ahve a 1998 2500 with poor heat...

Thanx,
threedodgetrucks

 

It might be screwed it could be glued either way you'll need to take the whole thing out to get it apart. Does the A/C work? It could be the plastic shield between the heater and evap core that is blocking the flow of air.

 

Thanx for the reply. A/C works fine and it blows great. I didn't know about a plastic shield between the evap core and heater core. Pulling the dash all the way is a bit of a pain, putting it mildly. Do you know of any pics of the inside of the plastic ducting where the evap core, heater core and blend door are?

 

For schematics and other info, search this site for the "merry christmas" thread, I think thats what they called it, it is a full manual on our trucks. BTW, if your mode doors are not moving, such as going from defrost to floor via the dash ****, you may have a vacuum problem to the switch. The mode doors are vacuum actuated. And yes, to get the hvac unit apart, ya gotta pull the dash out, and yes, it is a big pita. There are 5 bolts across the top of the dash, 1 on each side, and a brace in the middle bottom. The thing is heavy and awkward, so you'll need a friend. I just disconnected mine to do my heater core, but didn't take it all the way out, used a bunjee cord to hold up the right side enough to pull out the hvac unit. If I remember right, there are 3 vacuum modules on the unit, and 3 mode doors. I would check for vacuum problems first tho, just my .02

 

Can you point in the right direction to the "merry christmas" manual? I can't seem to find it. Thnx

 

Click here: https://dodgeforum.com/m_340929/tm.htm

Big D/L.

 

Absolutely outstanding!

Many thanx,