R Model, Cowl vent operation

[Full Floater]

So....the sticker on my factory heater blower motor says to use the cowl vent for ram air heating.  When I have the cowl vent open (there are no obstructions in it that I can see) I have very little ram air effect coming in even at highway speeds, so I end up having to use the fan anyways.

Am I missing something here in the cowl operation?  Is it normally as effective as the sticker makes it out to be?  Would be nice to have ram air instead of using the fan.

 

Thanks

[JoeH]

I've never bothered using mine, not even sure they work on our trucks.  I believe they open facing the windshield. Cold temps I just run the fan. Summer I use the roof and side vent plus the driver wing window.  

[Full Floater]

On 11/17/2023 at 3:13 AM, JoeH said:

I've never bothered using mine, not even sure they work on our trucks.  I believe they open facing the windshield. Cold temps I just run the fan. Summer I use the roof and side vent plus the driver wing window.  

Thanks.   Ya they seem redundant....I feel like they should do at least a little something otherwise they wouldn't be there, kinda like a Dynatard.   But maybe not.