I have a 2002 dodger ram 1500, 4.7 engine. Question is; recently got heater core changed on truck 1/12 ago. I did not do it myself, 'cause I was away for a while. I have heat, and it is blowing only off the passanger side,counsel, feet, and defrost. However, the air blowing out on the drivers side is cold. No leaks on the passanger side floor, or need to add antifreeze. I figured it is the Actuating valve (or door blend valve-if I have the right names. The mechanic told me I needed a new heater core, which I know is a big job. Again, noo leaks on floor , adn heat is sufficent....I would appreaciate any advice from you guys...fixsalot4u..........