1987 944 Turbo...........heater core electric motor, part number 063700-1001 and is marked DENSO. It's located on the driver side of the heater core and is used to rotate the rod that controls the air mixture temp for inside the car, typically where the white plastic clips break.

 

It could also be the heater valve is failing and they go into open position if I'm not mistaken.

 

Many parts on the HVAC system are actuated by vacuum - check the vacuum lines and the vacuum accumulator (black plastic thing by the battery). That's the cheap fix - if that doesn't work then you can look for expensive motors!

 

BTW - the motor/flaps you are looking at are for volume of air moved - not temp. If its just a temp issue then you are looking at a vacuum issue (or broken white clip)

See # 4,5 & 6

 

The way the system works in its basics is when you spin the temp **** a small motor is rotated which causes the flap to move and it allows a particular amount of heat and cool air to be mixed based on your setting. Most times this heat issue is cause by one of the rod clips breaking where your car will automatically allow heat to flow no matter where the temp setting is, this is because the motor im talking about pushes on a rod and that rod closes the flap from any heat mixing when set to full cold on the temp ****, so when the clip or rod brakes the flap is defaulted to being open fully allowing heat to enter, this design is to prevent you form freezing to death if it breaks in dead of winter on your ride home. However, since my motor is weak from 26 years of constantly holding the weight of the flap shut, the motor just doesnt have the power to hold it fully shut anymore (maybe half of the way), which allows the some heat to flow into the car when set on cold. If you want to test what im talking about you can park your car turn your key forward without starting it and turn the **** for the temp controll, youll hear a buzzing sound from the motor rotating its arm, opening and closing that flap, you may also note if you move any of the other temp controls a similar result will happen with the other flaps on the car for directing heat for windshield, center or floor output. The main motor is located under the driver side dash on the side of the heater core, right of the gas pedal. a plastic cover held by two screws covers it up. like I said most times when you always have heat and not vaccum issues, its because one of the rod clips broke, in my case the clips are fine but the motor doesnt fully close the flap leaving it mixing heat even when on cold. I was able to get this part for 40 bucks used.

Also, that is the wrong side of the heater core for this disscussion, the temp mixture motor (as I call it) is located of the other side which controls that flap to allow you to change how hot or cold the air is to your vents.
heres a link to the motor http://www.ebay.com/itm/251401098840...9#ht_61wt_1147

 

Denso made in japan is OE part.

 

Common for the little blue Check Valve coming off the Brake Booster to malfunction too, it's in the Vac Supply to the Heater. You can get most or all these parts from 944online.com, new or used.

 

bump, still looking for a motor

 

I've got one or two, let me see if I can find them.

 

Try either Lart or DCAuto. Both have wide inventories.

 

pm me if you have one