Fresh air vents plugged?

[GreyHoundSteve]

My cab is ready for primer and only one question remains .... What to do about the fresh air vents located under the dash?

My question is .... can i weld these shut?

It looks like they let air in from the cowl which i can see no purpose for other than letting a bunch of dirt and leaves into my cab and ruining all the effort ive made arranginf proper insulation.

Does anyone know if these vents serve any other purpose?

Also, there is a strange looking valve on the passenger side .... what is this for?

[chevydog66]

The valve on the passenger side is operated by the heater control. It is actuated by vacuum when the selector switch is moved to outside air.

[GreyHoundSteve]

Originally Posted by chevydog66

The valve on the passenger side is operated by the heater control. It is actuated by vacuum when the selector switch is moved to outside air.

So does that have anything to do with the vents there or it it just mounted next to them?

What im asking is ..... can i weld these shut and what would i lose if i did?

[red71cheyenne]

The passenger side air valve is kind of like recirc in newer vehicles. Except that it is bringing in outside air. You can weld it shut. I know Wes did his on his garden truck too. Unless you are concerned about being perfect for a restoration, I don't think it will make a difference. Now if you weld both of them up(driver and passenger), it should make the cab a little more airtight. If such a thing is possible in these old trucks

[GreyHoundSteve]

Originally Posted by red71cheyenne

The passenger side air valve is kind of like recirc in newer vehicles. Except that it is bringing in outside air. You can weld it shut. I know Wes did his on his garden truck too. Unless you are concerned about being perfect for a restoration, I don't think it will make a difference. Now if you weld both of them up(driver and passenger), it should make the cab a little more airtight. If such a thing is possible in these old trucks

That is EXACTLY my intention. I will be covering the ENTITE inside of the cab in a super insulating material and every peice of wheatherstriping and rubber will be new. So i can weld these vents shut and i'll only lose the outside air feature on the ac controls? What would happen if i flipped the ac controls to outside air and these are welded shut?

It didnt look like they were connected to anything. In fact, the driver side vent has a little rod that looks like it operates it?

[purple gas]

here we go again.. I live in Canada, where it gets cold,, colder than Indiana.. Here, if you don't have outside air coming in to your heating system you get a humidity build up that makes it impossible to defog the windows. The humidity comes from melting snow that inevitably gets in your cab if you live in a snowy climate, and also from your breath.(if you've ever got hot & heavy with your date on a cold night & steamed up the windows of a car you know just how much humidity is in a persons breath,,or if you ever used your breath to get moisture on glasses to clean them) if it's cold outside this moisture will condense on the cold glass creating foggy windows. If you don't have cold weather or don't intend driving in cold weather it might not be a problem. But if you do drive in cold weather you will have a problem keeping your windows clear if you just re-circulate inside air. depends where you live kind of.

[GreyHoundSteve]

Originally Posted by purple gas

here we go again.. I live in Canada, where it gets cold,, colder than Indiana.. Here, if you don't have outside air coming in to your heating system you get a humidity build up that makes it impossible to defog the windows. The humidity comes from melting snow that inevitably gets in your cab if you live in a snowy climate, and also from your breath.(if you've ever got hot & heavy with your date on a cold night & steamed up the windows of a car you know just how much humidity is in a persons breath,,or if you ever used your breath to get moisture on glasses to clean them) if it's cold outside this moisture will condense on the cold glass creating foggy windows. If you don't have cold weather or don't intend driving in cold weather it might not be a problem. But if you do drive in cold weather you will have a problem keeping your windows clear if you just re-circulate inside air. depends where you live kind of.

I'm in TX so if it snows one day out of the year i can take my car but i have incountered defrost problems before of vehicles and its no fun so your info is a big help. I guess i will go ahead and buy new seals and hope for the best but it seems like these vents will just eliminate any insulating material i may place in the cab because they dont seem to seal very well at all.

[724wdcopper]

the vents on my pickup seal pretty well, i have never noticed any air leaking by. i dont have AC, but a buddy of mine does, and he still uses the vents on warm days to cool his feet when AC is not really needed. i love them and just wish i could reach the pass side knob while driving (or have AC)

I'd definately keep them. the amount of air transfer is gonna be minimal at best. with new weatherstriping and insulating your cab, you should have no problems with cold air loss, especially through the vents.

[frogsmakr]

lol......I duct tape mine closed for the winter. The Vintage Air (heat) dont care bout fresh air. Thats what vent windows are for.

[GreyHoundSteve]

Originally Posted by frogsmakr

lol......I duct tape mine closed for the winter. The Vintage Air (heat) dont care bout fresh air. Thats what vent windows are for.

That was my thought process as well. If i need air then i'll turn on the ac. If i want air from outside the cab then i'll open a window.

Are you guys telling me that these vents are operated by hand and not the ac controls? I couldnt really tell because i never even noticed them until it was gutted. It looks like the driver side has a rod with a little rubber price but i didnt notice anything connected to the passanger side.

If they are operated by that rod and you have to reach up under the dash to open them then i'll weld them shut. If they are opened by the ac controls then i will just buy new seals. Does anyone know how they are operated?

[724wdcopper]

non ac cabs are operated by hand. there is a lever that connects to the center of the air door and just under the edge of the dash. on ac cabs, just the drivers side is manual, the pass side is operated by the ac controls. only opens when recirculating, i believe.

[GreyHoundSteve]

Originally Posted by 724wdcopper

non ac cabs are operated by hand. there is a lever that connects to the center of the air door and just under the edge of the dash. on ac cabs, just the drivers side is manual, the pass side is operated by the ac controls. only opens when recirculating, i believe.

Thats sounds about right then. Yeah i have an ac cab and the driver side has a little rubber peice on the rod so i assumed it was manual. The passanger didnt apear to have anything but as i mentioned .... its gutted. Hmm.... i guess i'll just have to see wherethe body guy is at come Monday. If he is ready to spray then i'll just buy new seals. If he has another day of prep then i'll have him go ahead and weld them shut.
Thanks for all your help guys.

[red71cheyenne]

The driver side vent is operated by hand. Its got a knob on it to pull it open. The passenger side is operated by vaccuum like chevydog said. If you put the lever on outside air it opens that vent via the actuator to the right of the heater core box. If you disconnect/remove that actuator and the associated vaccuum hose, you won't have any worries. As far as defrosting goes, mine always works better if I roll down the window a little anyway. Seems to create a little draft across the top of the dash. May be because my a/c and defroster suck, but thats beside the point. Jeff.

[GreyHoundSteve]

Originally Posted by red71cheyenne

The driver side vent is operated by hand. Its got a knob on it to pull it open. The passenger side is operated by vaccuum like chevydog said. If you put the lever on outside air it opens that vent via the actuator to the right of the heater core box. If you disconnect/remove that actuator and the associated vaccuum hose, you won't have any worries. As far as defrosting goes, mine always works better if I roll down the window a little anyway. Seems to create a little draft across the top of the dash. May be because my a/c and defroster suck, but thats beside the point. Jeff.

You guys are GREAT! Im installing power windows and im in TX so if i run into any defrost problems then cracking the window seems liek the way to go vs having to worry about these stupid vents which only seem to serve letting garbage and dirt into the cab.

[68LSS1]

I'm welding mine up also. Most all the new SUV's and and a few trucks don't have a "fresh air" feature anymore. There is still a vent position on the knob but that just recirculates. I will also weld up the area on the cowl. If you do that, I would also recommend putting a larger hole at the bottom of the box on the sides of the cab to make sure anything that does get in there comes out and doesn't start another corrosion issue. My thinking is the same as the above, that with the use of aftermarket a/c I shouldn't have a issue. If the windows fog up a little cool air will take care of it.

[GreyHoundSteve]

Yeah i havent figured out what im going to do about the cowl yet but it shouldnt be a hard fix.

[GSFMECH]

Thought I'd jump in here. Welding up the vent won't stop you from getting fresh air into the cab on the stock AC setup.There is another flap under the cowl. When you have the controls selected for outside air the vent in the pass side kick panel will close and the one under the cowl will open and directs the fresh air into the the fan where it goes through the AC/heater housing into your vents. When you select your controls to inside air the one under the cowl closes and the one in the pass side kick panel opens and directs the air that's inside the cab back up into the fan to recurculate the air back through your vents. If all the diaphrams and seals are good it should not leak. If you weld it up you basicly lose your ability to recurculate the air and your AC will only cool outside air. It would be better to leave it if you are still using the stock AC. A truck with just a heater only has a manual vent and does not work the same. Hope this helps.
Mike

[GreyHoundSteve]

Originally Posted by GSFMECH

Thought I'd jump in here. Welding up the vent won't stop you from getting fresh air into the cab on the stock AC setup.There is another flap under the cowl. When you have the controls selected for outside air the vent in the pass side kick panel will close and the one under the cowl will open and directs the fresh air into the the fan where it goes through the AC/heater housing into your vents. When you select your controls to inside air the one under the cowl closes and the one in the pass side kick panel opens and directs the air that's inside the cab back up into the fan to recurculate the air back through your vents. If all the diaphrams and seals are good it should not leak. If you weld it up you basicly lose your ability to recurculate the air and your AC will only cool outside air. It would be better to leave it if you are still using the stock AC. A truck with just a heater only has a manual vent and does not work the same. Hope this helps.
Mike

hmm.... I have a 67. I believe it to be an ac cab because it has holes cut for vents in the dash and they look to be factory holes. On my driver side kick panel vents it has a rod with a little rubber peice at the end. It looks to be manually controlled by this. On the passenger side there is a little thing with a vacum fitting. Are you saying that this is the factory ac set up or not?

My ac does not work currently because all of the under hood componets are missing and i havent decided if i am going to go factory or aftermarket this summer when i replace them. Would it make a difference on whether or nor i should permantly seal these vents?

Does anyone know where i can find a diagram illustrating the complete vent and ac system and controls?

One other thing that bothers me is that i ordered a "complete" rubber and mount and wheather strip kit fromm one of the vendors but the more i learn the more i realize thats this "complete" kit is missinf ALOT of rubber and seals.

[GSFMECH]

Sounds like someone converted the vent to manual. The stock AC trucks would have a vacuum controled diaphram to open and close the vent, but the way it sounds it is missing from yours. The stock AC can be made to work real well, the choice is yours if you want to go aftermarket or not. If you decide to go with the stock AC I highly recommend you keep those vents as the AC works a lot better when you can recurculate the air. The factory service manual will have all the info on your AC (with air flow diagrams) and can still be had from most vendors and book dealers.
Mike