Dodge Demon

Heres a tip for getting more interior heat, have 2001.5 but should work on all years, theres a setting on the heater controls that is "max AC", when in this mode theres a door just back of the glove box that opens by vacum so all circulating air is pulled from inside the cab,on all other settings this door is closed allowing only outside air accros the heater rad,I have a switch so I can operate my AC on any setting and also shut it completly off,I never have it kick in, in the winter, so the fastest way and to get the most heat from the heater is to have this door opened so the fan only draws inside air,but the problem then is that the windows fog up because of to much moisture in the air,the remedy is turn your heater control to "Max AC", drop the glove box door down,actually it will come right off,then you will see the vacum actutator which controls the door,the door will be opened and the acutator will be retracted,move the control away from "Max AC" and you will see the door closes and the vacum actutator rod is extended,the end of the rod almost hits the housing, move the control back to "Max AC" and put some kind of a spacer against the housing so the vacum actutator will hit against it ,thus holding the door partly opened so you get mostly recurculated and and a little outside air together,heater air is then almost twice as hot and still gets enough outside air to eliminate any fogging of the windows,for a spacer I used a piece of broom handle 2 inches long,actually lenght dont matter, at least 3/4 in or maybe a little more thick,hold this against the housing where the rod exteneds and switch the heater control to another setting, the rod will now extend and hit the spacer, thus leaving the door half opened, as long as you dont switch to "Max AC" the spacer will stay in place, now the ideal way to do this,and I probably will someday, is to disconnect the vacum actuator from the door and put a push/pull cable to regulate the opening and closing of the door,that way one could fine tune it,so to speak, to find the exact setting of the door that would give the maxinum heat and still have just enough outside air to eliminate any fogging of the windows, the 3/4 inch spacer, "broomstick" that I use does the trick for me,even when it was over 40 below F last winter, but who knows, with a full range of adjustment that the push/pull cable would give,it might even be better yet, I run my heater control on the setting which blows on the windshield and the floor and run the fan speed one notch from the top,only if its over 34 below F do I have to run it on high speed, I would like a setting that would blow air on the windshield,the floor and the dash vents all at the same time but theres no setting for that,mmmmm, might look into that.It used to be that when it was over 15 below F, whenever I slowed down the heater would blow luke warm air,not anymore.

infidel

Montana minds think alike, just posted the max A/C tip in the Cold weather air dam and fan? thread.
I never mess with the anything though, just cracking the window defrosts good.
I have 12 valves though which have a recirculate position, air comes out of every vent in this position.

Joe Diesel

i had this in mind but thought I was crazy guess not it does work, thanks to both for proving im not to crazy

jnicewan

The plenum chamber can get air from two places. Fresh air in all positions but MAX which is recirculated cabin air, if you run the MAX door partially open, the cold/fresh air can come through the cowl and then right through the MAX door and inside the cabin totally bypassing the plenum chamber and heater core and especially at higher vehicle speeds. At slower speeds and/or higher blower motor speeds you probably wouldnt notice much cold air bleed because the blower motor can keep up and direct the air through the plenum chamber. If you hold the door all the way shut you will be ok though. You may not notice this when driving but your passenger may complain about cold feet from the air bleeding past the MAX door into the floor area

Dodge Demon

You may be right but I drive in any and all kinds of weather and temps,and I have yet to have any passenger say anything about cold air comming in with the air door partly open,I have even tried it myself and there is absolutly no cool air comming in.Now,having said that,this is were a cable control on the door would eliminate any possability of cold air comming in,and one could adjust the door depending on the temp to eliminate any fogging on the windows and yet get maxinum heat in the cab.