I have a 96 3.0L dodge varavan that shoots out very little heat.
1) I have flushed the core by connecting a hose directly to the core on the firewall. water runs through core fine
2) I had the engine flushed twice.
3) New thermostat
4) The heater core is getting hot. I took out the plastic housing on the inside near the core and the pipes are HOT
5) Today I took out the electric motor that controls the flap for the temp (Up near the gas pedal). The motor is turning the "flapper" to 6) the full extents of travel.
6) I recently changed the water pump but the now heat has been the case for years.


Questions:
1) What role does the radiator cap have to do with low heat. A friend informed me to change the cap.
2) How do you get into the heater compartment? It looks like the entire dash has to come out including the stering wheel.
3) I have noticed that when I turn the heater kicks out more heat. This leads me to think that air could be in the heater core. How do you get the air out?
4) I was thinking that since the heater core is above the radiator cap that a leak in the cap could cause air to get into the system but wouldn't I see leaks?

If all else fails I am thinking about getting an old heater core and a motor and building a heater in the car.

Thanks.

Maybe the dash control knob is busted off on the cold side at some point in the dash.

The control knob seems to work. I move the temp slider to cold and the motor rotates the "heat flap" (down by the gas pedal), I move the temp slider to hot and the motor rotates the the oposite direction.

I need help on this one too. No heat. replaced thermostat, heat worked for a while, then after it stopped, I drained & refilled system, worked for that day, then heat stopped. heater core pipes are hot. wondering if i should backflush system or if it could be something else. haynes manual doesn't have any info about flap door for the heat box. im just getting any info i can from these threads to check that out. Please help.

96 Plym Grand Voyager, 3.3L V6.

I need help on this one too. No heat. replaced thermostat, heat worked for a while, then after it stopped, I drained & refilled system, worked for that day, then heat stopped. heater core pipes are hot. wondering if i should backflush system or if it could be something else. haynes manual doesn't have any info about flap door for the heat box. im just getting any info i can from these threads to check that out. Please help.

96 Plym Grand Voyager, 3.3L V6.


Oh yeah, I replaced the water pump this past summer as well. on the GV

sounds like a vacuum mode door is not functioning properly not allowing for heat to come in the cabin

Assuming the Water Temp is normal, the Blower Motor is OK and the Heater Core is HOT, it's gotta be Door(s) and/or switch(es).