heating

Everything is new radiator, hoses, thermostat etc. Only the water pump is the original that came with the truck... NO leaks, coolant level is good. The truck runs HOT getting up to 250 degrees unless I keep my temperature dial to the max heat setting, even then it will stay around 205-215...

I have an 02 ram 2500 4x4 that changes the air flow from the middle vents to defrost under acceleration. when I let off the throttle it goes back to the middle vents. this would suggest that the doors are controlled by vacuum. but my haines manual does not cover this. any Ideas?

I have 2002 Ram 1500 4.7L. I know of the relay switch needing to be replaced. I currently only have High on the blower. My main issue is the heater. The heat is warm for about 3 seconds and that is it. I see no leaks and I have replaced the thermostat. Any help I can get is much appreciated.

Air is cold and on high its humming very loud and the air is coming out like its on low. I read some other thread about a flap blocking the air. I bought a new blower because I live in Houston and it's freakin HOT!!!