Heat Defroster Question

[tkmoore]

It's cold here in Colorado...I have an 83 sc with stock 3.0 and all stock heater components. I haven't used heat or front windshield defroster yet this year because my engine heater blower motor was broken. Put in a good blower motor and confirmed it works. But, when i turn it on by pulling up the heater handled between the seats, I barely get and airflow coming out of the defroster vents or heat vents.

I confirmed the heat exchanger hoses are all connected, that the cables from the heater handles operate the rest exchanger heat doors fine (near rear shocks) and that the dash controls are set correctly. Even checker the cables and mechanisms under front trunk and all seems fine. Any idea on whether my poor air flow to the dash is normal? Or, any ideas on the likely problem? Thanks, Tim

[timmy2]

Does your car have the auxiliary blower motors in the ductwork on drivers and passenger side?

[James Brown]

is the blower motor working with the handles up? at best all you get is a small output at idle to 2000 rpm ish. This is why people back date there heat. there could be a hundred leaks in the system including leaks in the sills that are very costly to fix. The Carreras used foot well blowers to try to fix the problem, too little to late.
I bypassed all the heater/cold air smolts with hose from the footwell outputs right to the defrost vents. controlled with the levers between the seats.

[javadog]

Originally Posted by timmy2

Does your car have the auxiliary blower motors in the ductwork on drivers and passenger side?

He won't have those in an '83 SC. Porsche put them in the turbos first, the normally aspirated cars got them later.

I'd check to make sure that the blower motor in the engine compartment was blowing air the correct direction. If so, and everything is connected properly and the flapper boxes are closing completely, you should have all sorts of heat when driving. Don't judge it while idling in your driveway, drive it down the road.

JR

[tkmoore]

Javadog you called it. Believe it or not, the heater blower motor was spinning the wrong direction (clockwise instead of counter clockwise). I recently had it apart to fix a bad solder connection at the brushes. Apparently when removing the two screws that hold the motors' top plate to the magnet housing, you need to pay close attention to the exact orientation of that top plate. If you reassemble it 180 degrees the opposite way the motor will go back together fine and look correct but it will spin the wrong direction. Now I have air blowing into the cabin as it should. Thanks for all the input. Tim