I have my heater core out being repaired. When it goes back together I was considering omitting the rubber bellows and capping the end of the vent housing so the heater would use cab air only, Has this been done? Is there a reason to prefer fresh air over recirculated air through the heater?

 

 

That's why I ask because I don't want to find out the hard way.

 

Makes defrosting the windshield more finicky I would think. Especially in moister climates.
Some have done on their old Broncos, but most live in drier climates and don't drive their Broncos every day either. My own is that way, but it's set up with a newer A/C system and the A/C should make it a little better than just heat.
I'm still a little worried about it, and actually want to make it switchable between recirc and fresh. But I haven't driven this one often enough to have much real-world experience with the defrosting aspect.

Paul

 

It would be nice to have the ability to switch between recirc and fresh, very rudimentary these stock systems are.

I live in SoCal so I might could get away with recirc only, but much like myself I wish not for this Ranger to spend the rest of its days in the golden state of lost luster.

 

Having outside air makes a big difference in keeping the windows fog free. I know SoCal doesn't get too cold, but a cool rainy night is usually enough to cause windows to fog. Heat helps a little, but recirculated air doesn't get rid of the humidity in the vehicle as well as fresh air. If you have, or are planning on getting A/C, that will do a great job of pulling humidity out. Hope this helps.

 

 

I have not modified this. Only played with outside vent covers. Here's a few thoughts:

• There is a fair amount of push from outside air pressure when running down the highway. That will try to overwhelm the return path, and cold air will try to get into the cab, but not through the heater core.
• So, it would make sense to have a flapper on the inside, so that when pulled closed, it would hold itself closed under the 'pressure'.
• The 'recirculation' hole ought to be on the right/fresh side of the heater core, so warm air goes through multiple times.
• A plastic remote-control-airplane cable may be the right cost/durability for the control.
• The pull handle should be near the driver.
• Also blocking one of the vents in front of the windshield could be helpful. I did use magnetic sign material on a car, and it worked great. Do wax the paint before applying the vent material, as rust will occur on the backside. You will want at least some of the vent exposed, maybe half of one side.
• You will use this recirculation for the first ten minutes. After that, the heater should clear out the moisture and get you toasty fast.
• Even when working perfectly, I don't believe the defroster vents are adequate. A bilge-blower fan may help, but finding a good place to put it in the short defroster hoses is a challenge.
• I could take some pictures if someone is really interested in working on this idea.
• Don't forget to crack the window a little, to encourage more steamy exhaust to get out. In an unmodified system, this will encourage a little more fresh flow-through, once the temps rise.
• Your wet, snowy clothing will have to dry out too.

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