suee

I just noticed that with the heat switch off i still have hot air coming out of the center vent and the right side vent. I turned on the a.c. and still felt warm airmixed with the the cool air,what is going on?

GrantG

If you press the recirculate button (arrows making a circle on the top right), you won't get unwanted air in the cabin (otherwise it's like a vent).

aam993

I had the same issue - out of a sudden, with temperature **** control on the blue dot, with a/c off, hot air was coming from the central vents, even though ambient air was cool.
It turned out that my passenger side electric flap motor died - that flap, which controls flow of hot air from engine compartment into the passenger cabin stayed open. Once I replaced that electric motor(part #993-624-325-00), I got my cool ambient air back.

Jeremy Pinsly

I have a similar intermittent problem on my 1990 964. Is this motor replacement an easy DIY or do you recommend a wrench? How much did this cost you to replace?

aam993

Jeremy,

it is very simple DIY for 993:

take the passenger side cover off;
loosen the screws on the clamps, which hold the flap,
take the electrical motor off the flap - it is held by three long screws,
disconnect electrical connector from the motor,
put a new one and reassemble everything back together.

The motor for 993 is ~100$ from a friendly dealership(f.e. Sunset Imports in Oregon).

Good luck!

JasonAndreas

Roly Baldwin wrote up a pretty good article with LOTS of pictures for the 964 and it pretty much applies to the 993. To add to Roly's article, if you don't have a Bosch hammer just have someone operate the CCU with your car running while you stare at the 5 servo motors to see which one doesn't move.

Jeremy Pinsly

Thanks Jason..........