964 - Heater Flap Boxes??
#16
random hot air with ac on
My 93 C4 dumps ac works for a while, then will start dumping hot air. I replaced the heater motor relay . Good for a week then the problem came back . My shop guys say that the control head is the culprit due to the random nature of the problem. I had it repaired by ASI in 2012, so I do not believe sending it back will fix it. As a hot weather fix , how do you prevent the heater blower/flaps from opening ? My thanks for any assistance.
#17
Race Car
Originally Posted by alexjc4
Rather than start a new thread i thought that i'd post my q here, for future searchers.
I took one of my flap boxes out today, for non hvac related reasons, it was a bit stiff and was stuck in a half open position. I've given it a clean and a squirt and wiggled it back to life. My question is: how much resistance in the movement of the flap is normal?
I took one of my flap boxes out today, for non hvac related reasons, it was a bit stiff and was stuck in a half open position. I've given it a clean and a squirt and wiggled it back to life. My question is: how much resistance in the movement of the flap is normal?
#18
Check the servo ball joint connection
Hi jw964c4,
If I understand your problem, check the mechanical connections for the servo in the front of the car.
Good illustration here:
http://web.archive.org/web/200811152...3.%20Reference
The plastic ball joints can fail and will let the mixing flap open to full heat randomly. If it is the ball joint you may be able to fix it with zip ties until replacements arrive.
Hope that helps,
James
If I understand your problem, check the mechanical connections for the servo in the front of the car.
Good illustration here:
http://web.archive.org/web/200811152...3.%20Reference
The plastic ball joints can fail and will let the mixing flap open to full heat randomly. If it is the ball joint you may be able to fix it with zip ties until replacements arrive.
Hope that helps,
James
#19
Random AC
Thanks James944. Checked out the servos this morning. After 6-8 minutes with the ac on, the servo opened and the hot air started. I messed around with the recirc and defrost settings and the servo closed and I had cold air again. The temp button was on full cold all the time. Really a bummer. Would the flap stay closed if the actuator arm is disconnected? Any suggestions are really appreciated.
#20
Hi jw964c4,
My flap would not stay closed with with actuator arm disconnected, it would open to full heat randomly. In your case it does seem like a control system problem.
For the summer, what you could try would be disconnecting the controller connection to the servo (the 5 pin connection in step #7 in the link above) and see if the system cools properly (not sure how it's wired and maybe disconnecting a servos would cause an error). That way you would still have the servo holding the clap closed to cooling but no controller signal randomly opening it.
You would just have to switch it when it started getting cold,
James
My flap would not stay closed with with actuator arm disconnected, it would open to full heat randomly. In your case it does seem like a control system problem.
For the summer, what you could try would be disconnecting the controller connection to the servo (the 5 pin connection in step #7 in the link above) and see if the system cools properly (not sure how it's wired and maybe disconnecting a servos would cause an error). That way you would still have the servo holding the clap closed to cooling but no controller signal randomly opening it.
You would just have to switch it when it started getting cold,
James
#23
Rennlist Member
Good illustration here:
http://web.archive.org/web/200811152...3.%20Reference
http://web.archive.org/web/200811152...3.%20Reference
#24
Thanks James & Eddie, I disconnected the power lead as you said, the heat flap stays closed now. Can even run on vent now. I'll let you know if the control head can be repaired.
Jim
Jim
#25
Hello
I'm new to the rennlist. I have the opposite problem with my 964, in that the heater fan is always on and blows hot air into the cabin. Even if I have the blue position on temp control and fan in off position, i still get hot air blown in. Any ideas how to resolve?
I'm new to the rennlist. I have the opposite problem with my 964, in that the heater fan is always on and blows hot air into the cabin. Even if I have the blue position on temp control and fan in off position, i still get hot air blown in. Any ideas how to resolve?
#26
Rennlist Member
Hello
I'm new to the rennlist. I have the opposite problem with my 964, in that the heater fan is always on and blows hot air into the cabin. Even if I have the blue position on temp control and fan in off position, i still get hot air blown in. Any ideas how to resolve?
I'm new to the rennlist. I have the opposite problem with my 964, in that the heater fan is always on and blows hot air into the cabin. Even if I have the blue position on temp control and fan in off position, i still get hot air blown in. Any ideas how to resolve?
Servo 2 and 4
#27
Burning Brakes
I'd like to resurrect this thread once again - I'm getting hot air in cabin even if I disconnect the servos and manually close the heater flaps. I hear the little "tink" of the rear flaps when I open and close the doors. But something ain't right.
Just before weather started getting hot, the Freon was recharged and my indie (apparently) leak tested the A/C with no leaks.
A/C on does nothing - no cold air - but engine bogs a touch when turning on a/c - so something is turning on.
Will have to get it back to the shop and hook up to a Hammer. Hope I can get it sorted - may have to consider stuffing the rear heater vent hose/intake by the engine with insulation and disconnect the hose (previous owner did this and said it helped keep hot air blowing in).
No a/c, or rather, full heat all the time = no more 964 for me
Just before weather started getting hot, the Freon was recharged and my indie (apparently) leak tested the A/C with no leaks.
A/C on does nothing - no cold air - but engine bogs a touch when turning on a/c - so something is turning on.
Will have to get it back to the shop and hook up to a Hammer. Hope I can get it sorted - may have to consider stuffing the rear heater vent hose/intake by the engine with insulation and disconnect the hose (previous owner did this and said it helped keep hot air blowing in).
No a/c, or rather, full heat all the time = no more 964 for me
#28
@dr mitch, i see you are in Toronto. Did you get your heat/cool issues sorted? i am digging into mine and hope to have it solved. i have working heat and ac now but needs some tweaking...
#29
Burning Brakes
Yes, I did.
The heater flaps were sticking - I disconnected the hot air hoses (I replaced the old paper ones with nice duct tube from AirCraft Spruce) - I played with the flaps and there seemed to be a bit of grime / dirt in there - they seemed to work well - but would occasionally stick - so for the summer, I disconnected the hot air hose and put the foil tape over the intake to the HVAC - that made a HUGE difference in the amount of cold air in the cabin - so much so that my wife actually asks me to turn it down! (My servos used to stick, but I took them apart a couple of years ago and cleaned them and they all seem to be functioning fine now). Once the cold weather is here to stay I will reconnect the hot air hoses.
The heater flaps were sticking - I disconnected the hot air hoses (I replaced the old paper ones with nice duct tube from AirCraft Spruce) - I played with the flaps and there seemed to be a bit of grime / dirt in there - they seemed to work well - but would occasionally stick - so for the summer, I disconnected the hot air hose and put the foil tape over the intake to the HVAC - that made a HUGE difference in the amount of cold air in the cabin - so much so that my wife actually asks me to turn it down! (My servos used to stick, but I took them apart a couple of years ago and cleaned them and they all seem to be functioning fine now). Once the cold weather is here to stay I will reconnect the hot air hoses.
#30
Rennlist Member
Yes, I did.
The heater flaps were sticking - I disconnected the hot air hoses (I replaced the old paper ones with nice duct tube from AirCraft Spruce) - I played with the flaps and there seemed to be a bit of grime / dirt in there - they seemed to work well - but would occasionally stick - so for the summer, I disconnected the hot air hose and put the foil tape over the intake to the HVAC - that made a HUGE difference in the amount of cold air in the cabin - so much so that my wife actually asks me to turn it down! (My servos used to stick, but I took them apart a couple of years ago and cleaned them and they all seem to be functioning fine now). Once the cold weather is here to stay I will reconnect the hot air hoses.
The heater flaps were sticking - I disconnected the hot air hoses (I replaced the old paper ones with nice duct tube from AirCraft Spruce) - I played with the flaps and there seemed to be a bit of grime / dirt in there - they seemed to work well - but would occasionally stick - so for the summer, I disconnected the hot air hose and put the foil tape over the intake to the HVAC - that made a HUGE difference in the amount of cold air in the cabin - so much so that my wife actually asks me to turn it down! (My servos used to stick, but I took them apart a couple of years ago and cleaned them and they all seem to be functioning fine now). Once the cold weather is here to stay I will reconnect the hot air hoses.