84_Carrera

Ok guys, here's what I've got:

28 degree (F) day, sunny, so the top's down (I'm in Winter Denial).

I have defroster heat and Aux blower's working at the handbrake (full flaps up). I have no footwell heat. Help?

Saw a thread where Pete Z mentioned diving into the trunk & futzing with heater box controls... anyone got a picture or more info on this? The red lever moves side to side, but I have no lower heat regardless. I assume this is just like a spring or cable that's fallen off the lever?

Thanks!

J. Brinkley

do 84's have footwell blowers?

84_Carrera

Jerry -
I heard a "twang" type of sound when moving the red lever side to side awhile back. I assumed when I didn't feel any warmth on the toes that something had snapped or fallen off in the dash somewhere.

As for should I have heat, uhhhhh, I THINK I had footwell heat before...

J. Brinkley

have you seen this?

http://members.rennlist.com/imcarthur/911autoheat.htm

84_Carrera

Mine appears to be the manual heat layout (bottom of the page there).

No, I hadn't seen that site, thanks! Will look over it all now.

Amber Gramps

Fred, with you as my inspiration I dropped the top and braved the 84 degree weather and got chinese food last night.
My Bentley book was no more helpful than the website Jerry pointed you to.

Sean F

Two immediate things to check are the hoses and heater boxes. Make sure that the hoses are connected from the exchangers to the boxes and to the blower motor in the engine. Also, check the heater boxes to see if they are working properly. It may be that you snapped the cable, or they could be rusted out.

84_Carrera

Sean -
The boxes / cables were good (recently removed exchangers to replace exh. gaskets), and the "flaps" levers work fine, as always. The pass. side has a little more resistance than the driver's does, but they both open & close.

I do get heat, but only from the defrost vents. As it gets colder, I don't want to be chancing cracking the windshield with the heat there.

Sean F

Ah, sorry should have read better. I'm not completely familiar with a Carrera's controls, but assume they are similar to the SC. I'm going to guess that you already have the lower lever in the dashboard all the way to the left which would route the air to the footwell. If you do, then you need to get in the trunk and remove the air plenum cover. Once you get in there you'll see cables connecting to a kind of junction box. Not the large round one. I believe it is behind the master cylinder. I would imagine your cable has become disconnected here. This junction box routes the air based on moving the lever which pulls the cable and closes a valve. Yours is stuck in the defroster position.

Sean F

this probably won't come out very good, but here is a shot from the manual

84_Carrera

Thanks Sean!

I went out a few minutes ago (at work) and pulled the carpet back. Unfortunately, I don't have my tools here to pull the rounded panel back to see both sides of the Master, but on the driver's / fender side, I can see the footwel blower there, along with a cable-actuated slider of some kind. None of the levers I have moved will adjust the slider at all, though I can move it by hand. I'll play when I get back to the house, as I will have heat to feel at that point.

Tempted to pull it & see if I get any for the ride home, but will probably play it safe instead.

Thanks a bunch, much appreciated.

UberXY

Carrera heating systems are one of the great unsolved mysteries of modern physics.

Steve
84 Carrera

Sean F

There is a solution, I have it in my race car.....rip the bloody thing out

84_Carrera

Well, I think I'm pretty hardcore already, driving with the top down & frost on the ground, man. I've accepted no Cupholders. I've chosen no AC. I prefer no power steering, ABS, or stability control. But tunes & heat, I think I'll draw the line there.

Mysterytrain

The Carrera has an interesting heating system. There is an engine compartment blower and blowers in each of the footwells. There is also an engine compartment controller which includes a pair of relays, a reed switch and some logic circuits. Additionally, there is an over temperature sensor on the engine breather, a sensor on the drivers side heater flapper and Autoheat cars have an interior temperature sensor. The flapper sensor prevents the blowers from operating until the heated air is determined to be hot enough. The sensor on the breather turns on the rear blower when it senses that the engine temps have hit an overtemp set point while the engine is running but the car is stationary. Sounds crazy but its true.
There are a few places where component failures will prevent the system from working. The rear blower needs to be operational [Master] its current draw allows the footwell blowers [slave] to spin. These fans commonly bake to death. The footwell blowers are also known to fail do to heat, sometimes in a flaming way. They should be fused with 10 amp fuses. The 84 or 85 cars where fitted with inline fuses from the factory. You should perform this ungrade. The controller can also fail. More information then you will ever need is on this Pelican thread...enjoy the read.
http://forums.pelicanparts.com/showt...otwell+Blowers