My 81 targa heating system

[calimedeiros]

I just purchased my first 911 81 targa sc and my heat wasn't working well as it's still a bit chilly here in canada
So I decided to go into my heating system and just thought I'd share some of my experience with you guys
So you got 2 hoses that run from the rear of the car on each side that go into these 2 black heat plastic boxes in the trunk on each side
Inside these boxes are flaps that control the flow of heat and fresh air each box has 2 flaps so what controls these flaps
The top lever in your dash I only have one as mine is an ac car I believe if no ac then you should have 2 individual top levers
So my top lever controls the fresh air fan just turns it on off etc 3 speed I think
Middle lever controls one of the flaps in those black boxes in the trunk it opens or closes the amount of fresh air you allow to enter the car or get mixed with the heated air
The bottom lever controls the amount of heat coming from the 2 heating hoses just modulates the flaps
So I wasn't getting much heat I found that in those 2 heating boxes in the trunk the flaps were a bit seized I lubed them up and now they open and close
So all the 2 bottom levers do is modulate the flaps now I can leave my middle lever in the middle position and bottom leaver for heat in the middle position and I get 50 percent fresh air 50 percent hot air
Of course the heat will only work if one or 2 of the levers between the seat are pulled up

Hope this helps someone looking to get some heat before the hot weather hits

Top lever Fan only
Middle lever. Modulates fresh air
Bottom lever amount of heat you want
And I believe the middle lever also control the direction defrost only or defrost and feat or feat only

[bill's911]

How about a pic of your heater control panel?

[porwolf]

If it helps, here is the page in my '79SC manual that explains the dash heater lever system.

[HarryD]

The "official" explanation:

Thanks to RWebb, we do have the factory explaination as well :

It goes like this:

"There have been several questions about this recently, so I thought I would post the Official Factory Explanation:

Subject: RE: Heat Control FAQ for Pooschey


Q: I just bought a Pooschey 911 and can't figure out how to make the heater work -- or the fresh air either. Can you help me?

A: Sure, I can help you. The ventilation system requires that you operate 4 levers to make it work. 3 of the levers are on the dash, and the other is between the seats on newer Pooscheys there are 2 levers between the seats).

The top lever on the dash actually does several different things (remember, it is a fiendish German device, just like the rest of the car). Pushing it to the middle opens the dust ports leading to the windshield (see below for operation of fogging machine and oil mist spray device). Pushing it to the right past the middle also activates the rattling noise-maker device. There are three loudness levels to choose from. Pushing the lever all the way to the left is used to jam the cable so unauthorized personnel cannot operate any of the devices above. The lever also enables the automatic heat exchanger signalling device -- when opening it spews rust particles on the windshield, you should replace the heat exchangers. Also, if opening it causes you to immediately turn blue or purple (not just hair, but skin color) and become unconscious, you (or your estate) should definitely replace the heat exchangers.

The second lever from the top controls the lights on the White House Xmas tree. Move it to the middle to turn on the lights, and all the way to the right to fire 4500 Megatons of Nukes at Iraq.

The bottom lever on the dash is used to replace the windshield when it becomes scratched or pitted with rock chips. It also determines how much hot air goes to your feet as opposed to your head. For example, let's say the engine is completely warmed up and the hot air is burning your feet. If it's a cold day, you can flip the lever to the other side and shoot hot air onto the windshield so it cracks and shatters. Then call your insurance company (you do have insurance, don't you?)

The lever between the seats controls the oil mist spray device. When the engine is warmed up, this lever allows you to blow oil mist into the passenger cabin. Using the top dash lever lets you select whether you want the oil mist to coat the inside of the windshield or to just circulate around your feet. On a newer Pooschey, you have 2 levers on the floor between the seats. The left hand lever lets you open the left side vents which are aimed so they burn the feet of the person in the right hand seat, and the right hand lever lets you open the right side vents which are aimed so they burn the feet of the person in the left hand seat. Of course, each lever will also burn just the tops of the feet of the person in the other seat. If you are driving in the rain (or even stopped in the rain after the car has broken down), these levers also let you spray a fog of water vapor on the windshield, so no one can see in or out of the car -- sort of like privacy glass."

[calimedeiros]

[Windsor4273]

Thank you HarryD for the official explanation. After four years of owning my 911 I finally know what the middle lever does!

[RDM]

Your initial description is incorrect.

There are two "quantity" controls
- top lever controls quantity of fresh air
- lever(s) betweent the seats control the quantity of heated air via metal heater control boxes roughly above the back wheels

There are two "direction" controls- up (defrost) or down (feet). Note the arrows on the dash controls
- the middle dash lever controls the direction of the fresh air
- the bottom dash lever controls the direction of the heated air.

The air conditioning is completely independent, controlled by two knobs on the console. It only feeds through the dash vents

[calimedeiros]

I disagree

[RDM]

Originally Posted by calimedeiros

I disagree

With?

As I read Porwolf's factory manual, I recognize the description I wrote is for air conditioned cars. Cars without are very slightly different.

[javadog]

Originally Posted by calimedeiros

I disagree

Don't disagree too much... there are a lot of errors in your first post.

JR