Recirculating door and actuator? wife,s cold feet 1988

[lakesidedc]

I have a 1988 K1500. Solid good running truck. Drove it to Florida and back this year. Problem is on the passenger side where my wife sits, the cold air with the heat on freezes her feet. I stuffed rags and such any where I could see and opening. No help. After some research I learned how to access the door which I believe to be the recirculating door. As i opened the glued down panel I found the door standing open. I tried to move it but it would not.Might have been the fix, I don,t know. When I turn on the ignition, the door closes by the actuator motor near by. I feel pretty sure that is where the cold gets in, except I cannot get any action from it no matter where I set the heat/a/c or recirculate or defrost. It stays close key on. Opens key off. 1st Question is what exactly does this door do? Accessing it is a pain. I have disconnected the actuator in the closed position. I can see no light with a drop light in the chamber with the door. Am I missing something hear? were else could cold air get to her feet? Heat and a/c work great except when the weather is cold on her side. Long I know, But trying to get a good description up. thanks

[sntrym95]

The recirc door allows for cabin air to be blown across the A/C fins for maximum cooling. When the truck is turned off, the door opens to relieve the pressure from closing the doors by letting in air from the outside. When the recirc button is turned on via the dash controls, the door closes to the outside and the cabin air is passed by the fan across the A/C and heater fins.

When the door is open to the outside air, the face of the door is flush with the grate facing the passenger seat. When the door is closed to the outside, you can get your fingers in the grate and the door is set back a couple of inches.

If the door is not working properly, it could be the control unit in the dash or the door actuator. The door actuator can be replaced, but you will need a 1/4" air ratchet as a regular ratchet will not work - there is not enough room to turn it. I believe there is a foam seal as well, and if that has broken apart then cold air could be coming in even if the door is closed. You won't see light coming from the outside since the door doesn't have a direct path to the outside.

[lakesidedc]

I replied earlier but must have hit a wrong button. Anyway, thanks for the get back and your avatar is one of my all time favorite movies. When I got the glued down panel loose and looked in the door was straight up and open. Simply turning on the key closed it and nothing else i tried on the heater opened it again until I turned the key off. If that door is mainly for the decompression of the interior when you close the doors, and, I believe where the cold air comes in, what would I be doing to the system by disconnecting the actuator. Where does the system get its outside air from. Even that door we are talking about, has no outside air supply that I can see. dave

[sntrym95]

The outside air comes from under the cowl, down against the firewall and into that box. It's common place for leaks.

As far as disconnecting the actuator, you can do that but you won't have the option of getting fresh air in and the cabin air will always recirculate. I'm not sure what effect that will have on the HVAC control unit though, that's beyond my expertise.

Here is a diagram of the actuators: https://www.2carpros.com/forum/autom...cheater2_1.jpg

Towards the end of this video is the entire box removed so you can see where the air comes in: https://www.youtube.com/watch?v=N3pG4EzSlko

[stevejohnson48]

My actuators is or the control panel is out of commission so before winter or summer come in I turn the cold/ Heat door ( 90 Z71 )to one position and vise grip the door shaft ??/ I'm going with choke cables on both my levels and hot and cold actuators as they don't sell the control panel any more ??/

[lakesidedc]

Thanks Mike for the YT vid. I had watched some of it b4. What a crap system. Obvious dealer profits were a motivator. Mine is not that bad thankfully. Once I disconnected the actuator the only way I can see the air getting in is through the blower motor opening. The sound coming from the actuator on the vid were just like mine until I touched the door, now runs one way or the other fine. I just cannot trust it once I am miles from home and the cold air is coming in.
I have a 1965 f100 and a 1963 Pontiac. I don't think either of those cars have a "re-circulation" door. That is sort of why closing it down really does not bother me

[lakesidedc]

Originally Posted by stevejohnson48

My actuators is or the control panel is out of commission so before winter or summer come in I turn the cold/ Heat door ( 90 Z71 )to one position and vise grip the door shaft ??/ I'm going with choke cables on both my levels and hot and cold actuators as they don't sell the control panel any more ??/

No doubt cables made life simpler. Newer vehicles have no way to vent other than rolling down the windows or through the cowl. I will see how this works and the way the cold is holding on up hear, I should get on the road with the wife and find out b4 December gets here.

[lakesidedc]

Actuator disconnect was not the answer. It did stop the cold air getting in per my wife on a test ride. The heat worked good. The a/c not so good. Went from heat to a/c and I did get cool air but not like it was. I reconnected the actuator and I could not get it to open until I shut off the Ignition. It was probably stuck in the open position. The actuator has 4 wires so is controled by different operations. Not sure what. Maybe a small switch in the ground wire for cold weather.

[stevejohnson48]

Try disconnecting the battery for 15 min. maybe it will recalibrate ??/ Mine would but then after 2 weeks and several off and on's it was in the nill position ??/ sent some attachments maybe these will help ??/ remember there for a 90 Z 71 but I think all of them are the same 88-95 except the control panel ??/

[lakesidedc]

Originally Posted by stevejohnson48

Try disconnecting the battery for 15 min. maybe it will recalibrate ??/ Mine would but then after 2 weeks and several off and on's it was in the nill position ??/ sent some attachments maybe these will help ??/ remember there for a 90 Z 71 but I think all of them are the same 88-95 except the control panel ??/

You think its the computer system? I would not have thought the system would be that sophisticated. Maybe though. That actuator has 4 wires running to it. 1 black I believe to be a ground. I need to follow the other 3 to where they begin. Could be one of the other actuators making strange sounds causing the issue. Thanks for the break down.

[stevejohnson48]

Originally Posted by lakesidedc

You think its the computer system? I would not have thought the system would be that sophisticated. Maybe though. That actuator has 4 wires running to it. 1 black I believe to be a ground. I need to follow the other 3 to where they begin. Could be one of the other actuators making strange sounds causing the issue. Thanks for the break down.

There's a printed circuit board under the face plate I believe ??/ One GM parts guy told me to take it a part and use an eraser on the circuit board on all the contacts ??/ It worked for a month or so after I did that ??/

[lakesidedc]

Originally Posted by stevejohnson48

There's a printed circuit board under the face plate I believe ??/ One GM parts guy told me to take it a part and use an eraser on the circuit board on all the contacts ??/ It worked for a month or so after I did that ??/

Hmmm. I will have to take a look. thanks