Attention: TDR Forum Junkies 
The biggest problem with the Older Rams that use vacuum to close the recirculating door is that it only closes in AC Recirculating mode, and when its winter with heat on fresh cold air over rides your heater core. Here is my simple fix that cost about $50. 00 give or take. You need the following items.
A 80's area EGR Vacuum Switch, about six feet of 3/16 ID Vacuum line,about the same in 1/8 ID line. Vacuum check valve,plug to fit EGR switch, and a small Vacuum T, I found AutoZone. , bought switch on e-bay. Bestially you are going to take a vacuum line from T fitting on firewall that has a plug on one end, bring that to about two feet off Passenger side along windshield firewall. From inside bring the smaller vacuum line to meet that one, check valve will connect the two, larger side goes to T fitting Sorry for bad pictures, its pretty simple, you take the Vacuum plug off the accouter on door, that goes to one leg of small T, Vacuum Switch has three ports, one is an intake and left alone, the other goes to the line under hood, the top one goes to T. Now when you apply 12 volts to the Vacuum switch while engine is running, the door will close in any position, when off heater control acts normal. I have not done my switch yet, I plan to have two switches, one for the door and another to turn on AC compressor so if window fogs with door closed in floor mode. This fix is more civilized and works great!
Rick
A 80's area EGR Vacuum Switch, about six feet of 3/16 ID Vacuum line,about the same in 1/8 ID line. Vacuum check valve,plug to fit EGR switch, and a small Vacuum T, I found AutoZone. , bought switch on e-bay. Bestially you are going to take a vacuum line from T fitting on firewall that has a plug on one end, bring that to about two feet off Passenger side along windshield firewall. From inside bring the smaller vacuum line to meet that one, check valve will connect the two, larger side goes to T fitting Sorry for bad pictures, its pretty simple, you take the Vacuum plug off the accouter on door, that goes to one leg of small T, Vacuum Switch has three ports, one is an intake and left alone, the other goes to the line under hood, the top one goes to T. Now when you apply 12 volts to the Vacuum switch while engine is running, the door will close in any position, when off heater control acts normal. I have not done my switch yet, I plan to have two switches, one for the door and another to turn on AC compressor so if window fogs with door closed in floor mode. This fix is more civilized and works great!
Rick
