Hello, I have a problem with my 92 Dakota. Last winter my truck got nice and toasty inside and now it well.... doesn't. I have flushed out the coolant system, thermostat is new, truck warms up fine. I recently changed out to a different heater control unit do to the old one being broke (the vent selector was stuck on defrost.) I think my doors for selecting which vent to use are stuck partway open, or I have a leak in my vents somewhere. When I drive down the road I can feel cool outside air blowing in threw whichever vent is selected even if the temperature gauge is set all the way to hot, and when I turn on the heater its comes out sort-of warm, like its mixing with cool air. It also slightly blows cool air out the face-level vents when I have the heat on the floor. If that might be the problem, what is the easiest way to get to the doors? If not what else might it be?

 

Ya sounds like the doors or the cables to the doors are stuck. Unfortunately you may have to remove a lot to get to where you would need. The FAQ in this section has the service manual. There is a heating, AC section, that would be your best bet for info.

 

Thank you so much! You're a lifesaver.When I get time to check it out between college and work I'll let you know how it turned out.

 

The blend door is vacuum operated, as are the other doors. They are in the heater/ AC box which is buried under the dash. To get to the doors, you either remove the dash, or try to sneak the box out from under the dash. First though, I would check your heater hoses to make sure both are nice and hot when the truck is fully warmed up. If one is hot, and the other is luke warm or cold, chances are the core is plugged up. The hoses are accessible under the hood.