[&:]Having trouble with the heater in my truck.Can't figure out what the problem is.Get just a little luke warm air. Both heater hose's feel hot. Flushed the hoses and put in new thermostat. Still, No heat! Anyone know anything about this? Thanks

 

your heater core is plugged...

take off both hoses and flush it by itself... forward and backwards (back flush it).

 

Already flushed the core. Temperature gage runs around 200 degrees, but usually it always goes way up to 240 or 250 degrees at first and then drops back down to 200 and stays there. i just don't get any heat.

 

how was the flow out of the core? if it wasnt strong, then it's still plugged...

 

If both your hose into the core and out of the core are hot, it may be the air mixture door may be stuck. May not be allowing enough air to flow over the core and is bringing in more cold air to the mix.

 

Thanks for the info, I'll tell my friend about that. He was having similar problem with his heater.

 

I had the same problem with mine. It turned out to be a broken heater door. Apparently there is some servo that operates a door that closes off the door when then temperature control is closed to cold and open when its hot. There's good way to test to see if the door is broken. When you turn the ignition on, and if you hear the servo continually running, then the door is broken and will need to be replaced. The door on these trucks are plastic and over the years between the hot and cold temperatures, the plastic become brittle and breaks... The heater door is located in the box underneth the glove compartment. Good luck replacing it. You will need to remove the dashboard in order to get the door...

 

I have been having a recent issue with the heater in my 2002 RAM 1500 oscillating between providing an excellent supply of (borderline too-hot) heat, and then providing virtually no heat. The process seems to be tied to the position of my accelerator. When I place a load on the engine by depressing the accelerator, warm / hot air starts coming from the vents, when the heater is turned on, and the temperature gauge set to max heat. As soon as the truck runs at idle, or reduced load, the temperature of the air coming from the vents drops very quickly. If I depress the accelerator somewhat, the warm / hot air kicks back in. I do not recall this happening anytime in the past. The thermostat was changed a month or so ago, so that shouldn't be the problem. Any ideas? Thanks.

 

I found out what the problem was with my Ram 1500. The coolant level was low, which lead to the temperature cycling. I replenished the anti-freeze / water mixture, and the problem disappeared. I hope this bit of info may be helpful to others.

 

Sounds like a vacuum problem somewhere. I'd look at the lines (which should be good, given the age of the truck). I would especially inspect the check valves. That may be where the problem is.


Good luck.