Fan switch doesn't blow hot hair

When I have everything set for heat or defrost, and I put the fan on, the fan always blows outside air. IS this the way it's supposed to be?
If it comes from the black blower mounted on the engine, then is that the only fan that pushes the hot air in? Or is the one up front also supposed to help force that air in? Luckily, I live in CA, or I'd be freezing my ass off.


------------------
Kurt B
1984 911 Carrera Cabriolet
75 914 1.8

I have had the same issues with my 87 and realized how to properly operate the HVAC system given the last cold days here in NC.

On my car, if I slide the dash vent and fan levers off of full left, outside air comes in (thus cooling the heated interior). If I leave the top row 2 levers all the way left, and the bottom 2 rows right (indicating both dash and foot airflow), plus pull both heat levers, and possibly turn the switch on the console above the levers to 2 or 3, I get the most heat in the interior.

Hope this helps.

As long as the top lever (which is for fresh air only) is to the left it sounds as if you have a hole in your heater hoses at the back of the motor or the cables may be broken at the heat exchangers for directing the hot air in instead of dumping it out

Or maybe a rodent/bird/insect nest blocking air passage alltogether!

On a lighter note ... is that switch that blows air a recent development, Kurt? Must be kind of a complicated switch assembly ... how big is the flex hose going to the switch? Tiny little directional vents, too, I bet!

------------------
Warren Hall
1973 911S Targa

For some reason that's the one part I can't figure out on my 78SC. I feel your pain, but also like you, I'm in So Cal. so it's no big deal.

Haha Warren...no, it's not super complicated, but it's not just a button that says "Heat" with a knob that says "Fan" allowing me to reason "Heat + Fan = Warm interior"
All I know is, if I want hot air in, the fan has to be off. The fan switch moved to the right does turn a fan on blowing outside air in. Didn't anyone at Porsche think it might be kinda neat if you had the heat ON and you put the Fan on, the Fan would blow Hot Air into your car?


------------------
Kurt B
1984 911 Carrera Cabriolet
75 914 1.8

The front fan (upper lever) is for fresh air only. The lower lever (red) is for defrost or feet. The lever between the seats is for heat. Pulling it up controls the amount of heat diverted into the cabin. Pulling it off the bottom stop automatically turns on the blower motor in the engine compartment. Just remember that for heat you move the red knobs. Red = hot. Pretty simple. The dark knobs should be kept to the left for max heat. BTW don't you have an owners manual?

Yup ya can tell the seasons have changed! Very few air conditioning questions. It deals with heat now that we've had some chilly days here. I have the same problem but if I count correctly you have 4 levers on your heater control on the dash. I must've been cheated in my 79SC because I only have 3 slide levers. The top one operates the blower motor located in the trunk. I also have the two floor mounted "pull up" levers which open the heater boxes. I too am experiencing the heat loss when I turn on the trunk mounted blower (top slide lever). Maybe I don't understand the system but isn't that motor just supposed to supply more "force" to the heated air? For example when you need to set your defroster on high? All mine does is supply cool air. Or is the blower motor in the engine compartment supposed to supply all the force?

------------------
Howie
79SC

The blower in the trunk blows only outside air. Its intake is the black grill between and just forward of the windshield wipers. The only HEATING AIR blower is the fan in the engine compartment (plus the engine fan which blows THRU the heating air blower). Later 911's -- don't know when it started --have supplementary heating blowers under the dash.

I am glad to hear that others are experiencing this same problem! I can't get hot air, I live in Germany--where it is getting REAL COLD, and I can't read the owners manual or switches (they are printed in German). Man, I feel so much better now! But I do know that I have some heater hose tears which I'm replacing and I hope that is my major problem.

I also have three rows of slide switches but 4 slides. The top row is divided in half. The right half operates the fan in the trunk, the left half, I believe opens/closes the fresh air vent. The bottom two adjust the defroster and floor vent--the best I can figure! Did I understand you correctly that the engine compartment fan is suppose to come on automatically when the red handles between the seats are raised?


------------------
ASKram
askjbsa@yahoo.com

When these heater systems work properly, you have to keep them turned down, or drive nude. I keep them turned down.

I also keep the middle knob to the right, so that any fresh air will go past the windshield, and then open the fresh air vent (upper knob) if any fogging appears on my windshield.

------------------
'83 SC

The electrical fan in the engine compartment should always work, regardless of the position of the two levers located between the seats. The two levers between the seats, one for right and one for lever, just open the heater boxes by cable.

Unfortunately the electrical fan in the engine compartment of my 911 is not working. Apparently a common problem since the fan is running all the time when the engine is running (when the ignition key is turned)

The electrical fan that is located in the trunk will only blow fresh (cold when it is cold outside) air into the interier of the car.

Hope this helps



------------------
Joris
75 911S
http://members.xoom.com/joogie/Joogie.htm

Hey,
Does anyone know where to get one of the fans that goes in the engine compartment for the heater? Factory fans are about $300. Any aftermarket fans out there?

Mike Miller
89 911

ok guys,
I had the same problem the way i solved it was, to have someone pull up and down on the leavers between the seats you will need to be under the car, at this point you can see if the butterfly is opening and closing correctly, "due to rust" you may have to spray some lube to loosen it up check both sides make sure they work if you want heat.

I have been doing this exact battle today and have also read the owners manual.
If you pull up on the rubber boot around the two heat levers between the seats, you will find 2 tiny contacts that "make" a connection as soon as you pull up either lever or both. This runs a relay in the engine compartment which in turn turns on the auxiliary heat blower fan. It is protected by a 25 amp fuse just below the relay. I learned today that my fan does not work as the windings measure "open" with a meter. I still get a sufficient quantity of heat since the main cooling fan forces air through the heat exchangers into the cabin.
Next: The manual explains that the black levers in the dash control fresh air from the front. It is not heated so leave both those to the left. The RED lever allows the warm air to be diverted to the feet or windscreen.
As soon as I figure out what to do with my motor or what is a generic replacement, I will advise.

George Wroclawski
83 911SC
95 XJ6

That's right. Cool air will not come in when the top, black lever is all the way to the left. Maximum cabin heat happens when both red levers between the seats are pulled and the red lever on the dash is all the way left.

Moving the red lever to the right sends some hot air up through the defrost vents. I usually keep the middle (black) lever to the right. that way, if I open the vent (top, black lever) and maybe turn on the fresh air fan, it blows across my windshield. I use this cool air every morning to avoid windshield fogging.

Once you get going on a longer trip, I sometimes line all three dash levers aobut 1.5 inches from the left end. This ventilates the car nicely with warm, but not hot, air.

------------------
'83 SC