AuroraGirl
Full Access Member
- Joined
- Sep 8, 2019
- Posts
- 9,693
- Reaction score
- 6,869
- Location
- Northern Wisconsin
- First Name
- Taylor
- Truck Year
- 1978, 1980
- Truck Model
- K10, K25
- Engine Size
- 400(?), 350
My '69 and '70 Impalas have the Astro Ventilation. It was a new feature for '69 as it replaced the wing windows. The cars had dash vents on each side even if no AC. There was a second knob on the kick panel that you would pull out and outside air would flow through the dash vent. You can have air flow through the kick panel, or the dash, or both. The blower on those cars doesn't run all the time.
found bucket explaining itMy '69 and '70 Impalas have the Astro Ventilation. It was a new feature for '69 as it replaced the wing windows. The cars had dash vents on each side even if no AC. There was a second knob on the kick panel that you would pull out and outside air would flow through the dash vent. You can have air flow through the kick panel, or the dash, or both. The blower on those cars doesn't run all the time.
idk if this guy uses forum anymore but the answer to his questioning about the dust is valid on the "what was the reason" however the idea is that youre always going to have air coming into the cab and then leaving....I think the reason for the constantly on fan was to always allow fresh air into the cabin for recirculation and more importantly rid the cabin of exhaust fumes. I doubt that the GM engineers were concerned with keeping dust out. Thats a seriously funny theory though...lol
If by a slim...really slim chance that the GM engineers were in fact concerned with dust in the cab, it would make more sense to engineer better door seals. It is called a "fresh air vent" which by definition draws outside air in the cab. If its dusty outside...why design a system that draws in outside air ?
ANYWHOO...on a serious note to the o.p. YES the fan runs all of the time unless you bypass the system as it was originally designed and cut power to the blower fan. Most people, myself included also install an inline shutoff valve into the heater hose. When the inline valve is closed, it prevents antifreeze from circulating through the heater core. Since the fan is constantly on, without the inline valve, hot air will blow into the cab. In the winter time I open the valve and have heat. This modification is also helpfull if the heater core takes a **** and leaks into the cab.
thats simply necessary for 1) survival 2) physics 3) earth????
but, the dust thing, if your driving in dust, youre going to get dust inside. you happen to be driving a vehicle and ramming it into the atmosphere and your cabin is very still, that air is gonna get pushed the **** out by air making itself known to you. this is going to get dust in there. if you have a fan blowing its going to always be pushing out and leaving in a controlled manor, which in a dusty road maybe wont change much but a constant flow through is just probably going to do less than still.
Go get an air purifier and put it in a house with a woodstove.
youll find that dust accumulation is cut down a lot and its not exchanging air inside to out, its just pushing whats in side around, but through a filter. if you found a way to put a cabin air filter(youve heard of those, yeah!) you would do something probably.
Also, an ac truck gets a recirc function, if you had that and a filter on the inside mix from outside, you would get no dust(relative) so yeah.
i understand the air doors on manual heat trucks exist.
I also want to say that you can just get a 4 speed switch from a later truck like the 80s and not connect the low speed wire to it(apparently) and fix the annoyance if you desire because you will have an off switch in the speed controls I think.
I will be doing that.
Also, the biggest concern with regards to fuel, exhaust, can be mitigated by proper hood to cowl and cowl and firewall insulation/seals.