1982 244 fresh air delete

I am three days deep into blower motor replacement, going slowly, taking my time, tidying things up a bit. A thought has occurred to me. I have no need EVER for the heater and I would be operating the A/C in recirc mode always. I'm thinking, for the sake of efficiency and reliability, I could permanently rig all the diverters to their proper positions (blow out the front vents) and cap off the vacuum system at the manifold. The only thing I am not sure of is where would I rig the fresh air/recirc door to close off outside air from coming in? Is it accessible from where I am at now or will I have to go deeper into the heater core area? Anybody have any thoughts on this?

Just cap off the vacuum port at the manifold. As long as there's no vacuum to the system, the fresh/recirc flap is in the recirc mode and the dash vents are open with the defrost and floor vents closed.

John242Ti said:

Just cap off the vacuum port at the manifold. As long as there's no vacuum to the system, the fresh/recirc flap is in the recirc mode and the dash vents are open with the defrost and floor vents closed.

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As someone who’s encountered this unintentionally, I can say this approach is very effective. It also made for a very foggy car, but I think that’s also a wrong-coast problem.

Perfect, I will just cap it....thanks!

Don’t all hvac system default to defroster when there is a problem? Like no vacuum.

Recirc mode can get a bit funky smelling if it is always on

2 old for this said:

Don?t all hvac system default to defroster when there is a problem? Like no vacuum.

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My 240 defaults to just dash vents without vacuum. Not sure if this is consistent across all model years.

Unfortunately I know this from enduring a northeastern winter with a leaky vacuum hose that ran from the check valve on the intake to the vacuum reservoir behind the dash. It took me a while to figure out why only the dash vents worked, and during that time I was stuck ?defrosting? my windshield by hand with a microfiber towel

1973-93 100/200 series Volvos with the three button climate unit default to dash vents and recirc mode if the vacuum hose is disconnected.

2turbotoys said:

Recirc mode can get a bit funky smelling if it is always on

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Hopefully the OP doesn't delete the fresh air vents on the kickpanels. Those can be opened to allow fresh air into the car when AC isn't needed. If the car doesn't have a passenger fresh air vent, they're actually pretty easy to add. Just need to find the vent panel from a non-US or a Diesel car, then install a driver side vent flipped upside down in place of the metal plate that covers the hole, and install the vent panel. The constant idle and Lambda boxes will need to be mounted to the firewall or to a bracket behind the glovebox, so they aren't sitting on the passenger floorboard the whole time.

Nice, good tip. I would like to add the kickpanel vents to my '78.

It's worth doing. If your '79 only has the driver's side vent as well, I'd get two panels and two vent assemblies, then modify that car as well.