Heater Box Adjustment
Thread Starter
Pro
Joined: Aug 2002
Posts: 686
Likes: 1
From: SLC, UT
Heater Box Adjustment
Looking for a bit of insight and help on how to adjust the heater box flaps. Vitals: '86 Carrera and has the automatic heat switch (no levers) between seats.
Last night I was under the car and noticed that the heater boxes were open as they should be with the blower motor off. I sprayed each with WD40 just to make sure they were lubed well and operating smoothly. I could manually rotate the flaps on each so they closed completely and when I released the flap on each, the spring would pull the flap back open (I assume they are working correctly). I decided to see how it worked with blower motor on. I put the switch to the highest position in the red which is 10. With the blower motor working as it should, I crawled back under the car to see if the flaps closed all the way. They were still open about a quarter of the way and I could feel air blowing out. My questions are:
1. Is this the way they should be or should the flaps be closed all the way when the blower is running on high?
2. If the flaps are suppose to close completely, should I adjust the cable on the flaps themselves, as there is a lock nut similar to a hand brake on your kids bike, where I can pull the cable and make it shorter, thus forcing the flaps to close or, is there an adjustment in the switch assembly between the seats that will accomplish the same?
Both left and right flaps are open about the same which tends to make me think that there may be one adjustment for both.
Sorry for the long post.
Help and input is appreciated.
Last night I was under the car and noticed that the heater boxes were open as they should be with the blower motor off. I sprayed each with WD40 just to make sure they were lubed well and operating smoothly. I could manually rotate the flaps on each so they closed completely and when I released the flap on each, the spring would pull the flap back open (I assume they are working correctly). I decided to see how it worked with blower motor on. I put the switch to the highest position in the red which is 10. With the blower motor working as it should, I crawled back under the car to see if the flaps closed all the way. They were still open about a quarter of the way and I could feel air blowing out. My questions are:
1. Is this the way they should be or should the flaps be closed all the way when the blower is running on high?
2. If the flaps are suppose to close completely, should I adjust the cable on the flaps themselves, as there is a lock nut similar to a hand brake on your kids bike, where I can pull the cable and make it shorter, thus forcing the flaps to close or, is there an adjustment in the switch assembly between the seats that will accomplish the same?
Both left and right flaps are open about the same which tends to make me think that there may be one adjustment for both.
Sorry for the long post.
Help and input is appreciated.
Instructor
Joined: Jul 2003
Posts: 186
Likes: 0
Flaps....
On my 78 I adjust the flaps in the fall so that they will be full open to heat flow to the cabin. In the spring I readjust them to be fully closed, dump all the heat out to the roadbed.
Too much slack in the system....
On my 78 I adjust the flaps in the fall so that they will be full open to heat flow to the cabin. In the spring I readjust them to be fully closed, dump all the heat out to the roadbed.
Too much slack in the system....
Instructor
Joined: May 2003
Posts: 117
Likes: 1
From: Edmonton, AB, Canada
Adjustment is made under the car at the cable end. There is a small clamp that holds the end of the cable sheath to the box. Loosen the clamp, slide the cable sheath through until the flap is open the appropriate amount, and then tighten the clamp again. (From memory, you need about an 8mm wrench).
Burning Brakes
Joined: Nov 2002
Posts: 801
Likes: 6
From: United Kingdom
It depends how 'warm' the car is in the cabin - the setting may well be on '10' but if the cabin is already hot the flaps will not fully close anyway.
Assuming the test was with the cabin at a reasonably ordinary/low temperature then the flaps should be fully closed to allow max hot air flow to the cabin - as Paul says, adjustment is at the flap end.
PJC
Assuming the test was with the cabin at a reasonably ordinary/low temperature then the flaps should be fully closed to allow max hot air flow to the cabin - as Paul says, adjustment is at the flap end.
PJC
