Heater controls.

[Porsche 2]

My '87 911 Carrera Cabrio has both the rotating dial automatic temperature controller, and the two red handled manual controllers next to the emergency brake lever. Neither the owners manual or Bentley's service manual shows this combination. Is this standard, and how to operate? (Heat comes on with with the engine electric fan running by use of the levers).

[DRACO A5OG]

The Red levers switch the engine compartment blower motor and foot blower motors. It also controls the flapper boxes intake of not air from the heat exchangers.

The center dial is for volume of hot air. You have auto heat which is controlled by temperature sensor in side the cab.

[Porsche 2]

Thanks for your prompt response. How does the auto. dial control the volume of air, as the levers appear to also control the "flapper" valves?

[Stutzdriver]

The RED handles controll the opening and closing of the flappers therby controlling th amount of hot air directed forward. When everything works right when you pull up on either (or both) red handles the engine blower activates pushing hot air through the heat exchangers and through the flappers. You turn the dial for the fan speed of the footwell blowers (1= low; 2= Med; 3= high). The dash controls direct the air around and the fan switch on the dash controlls another fan that basically is for the windshield.
T took a while for me to figure this all out and make everything operative on my 84 Targa but noe that its right you can keep plenty warm to the point where we open a window to keep thing temetrate. We have driven a cool noght (45 degrees) with the Targa Top off and theheat blasting warm.



Good luck getting it all operating correctly!

[DRACO A5OG]

I believe he has the AutoHeat option where the cabinet sensor control the fan speed.

[86 911 Targa]

Originally Posted by Porsche 2

My '87 911 Carrera Cabrio has both the rotating dial automatic temperature controller, and the two red handled manual controllers next to the emergency brake lever. Neither the owners manual or Bentley's service manual shows this combination. Is this standard, and how to operate? (Heat comes on with with the engine electric fan running by use of the levers).

If you have the three speed blower control, it is manual heat
where the levers control the cabin heat.

For the Auto Heat, you would have ten blower speeds
controlled by the rotary switch.

The cabin sensor only controls the Auto Heat temperature, not the fan speed.

[DRACO A5OG]

^^^ There you have it :-)

[darrin]

does it follow then that a carrera with autoheat would, by definition, lack the two red levers between the seats? Put another way, if the OP has two red levers, then he has manual heat?

[Porsche 2]

Just checked, the round dial does indeed have three positions that control the fan speed. So it is a manual system with the two rred handled levers that switch the fan on and control that volume (flapper valves). Thanks for the help.

[DRACO A5OG]

Originally Posted by darrin

does it follow then that a carrera with autoheat would, by definition, lack the two red levers between the seats? Put another way, if the OP has two red levers, then he has manual heat?

Even with autoheat the two Red levers activate the foot blowers via the sensors auto heat dial.

[darrin]

thx Draco!

[Porsche 2]

Draco, Auto heat does not have the two levers, per the owners manual for my 87 which shows the turn dial with plus 6-7 positions, versus my actual manual set up with two levers and only three positions for the turn dial?

[DRACO A5OG]

I stand Corrected. Hmm I thought I saw levers on my buddy's 88 with autoheat. Well that is good news.

[javadog]

Some years there was a lever with the auto heat controller, to use in case of a malfunction. One lever, not two.

JR

[DRACO A5OG]

^^^ huh? Maybe that is what he had???

[javadog]

Noooo...