Ok everyone I bought this new to me truck a month or two back well i didnt check the heat.....why didnt i check the heat! One might think that a 03 should have normal heat...think again my ram is a cold heartless BI#CH in the winter. After a bit of searching around on here I think its gotta be one of two things. Either the blend door or a clogged heater core.

If the heater core is clogged will both lines going through the firewall be hot?

Should i just try to unclogg it anyway?

Please help

Sincerely,

A COLD ****

 

If both hoses are hot, it's flowing coolant. I would say blend door.

 

How would i test the blend door?

 

Were both hoses hot from the heater core? That's the easy thing to check first. Check out heatertreater.net for everything you want to know about the blend doors. But basically if you had moderately cool AC (not as cold as you would think it should be), not very warm heat blowing, or the third tell tale sign is if the passenger vents are different temps than the drivers vents. All the air boxes are identical, and for trucks without dual climate control, both blend doors are linked together (well, until they break). In your case it seems that both the blend doors are stuck in the full cold position (pending results from your heater core hoses).

Here's something else to try, key the ignition to the on/run position (don't start it), wait about 20 seconds for everything to settle down and stop beeping, then rotate the climate dial to full heat, listen for the blend door moving. then change it to full cold and listen. also change it between floor to center vents, and also defrost mode. You should be able to hear the re-circ door, blend door, mode 1 and mode 2 doors operate. They are quiet but after doing that a few times you should be able to tell the sound of a functioning door as it moves and seals in position.
The re-circ door is behind the glove box, the blend and mode 1 doors are just to the right of the center console, and the mode 2 door is on the left side of the center console.

 

For being 8.5-9 years old, I would say your blend doors lasted quite awhile LoL