Getting heat BLASTED

[Buckskin7T7V]

Where else can the hot engine air get into the car ventilation ducts? I have a 77 with A/C. I have replaced the hood weather stripping. Hot engine heat is getting into the ducting somewhere and when I turn on any setting: Vent, Heat, Def. A/C , MAX. I get hot air. The temp control lever is in the cold position. The A/C compressor went out and it is not belted up. I understand the outside air comes in on the passenger side, in the windshield cowling behind the protective plastic screen. I can see the blower fins. Somehow hot air from the motor is getting sucked into this ducting and blows into the car. The heater hose are blocked.ad

 

[john1977]

The valve on your heater hose, that is controlled by vaccum from your ac/vent/heater control is probably not pulling the haeter hose valve closed. This is why you are getting hot air all the time.
Either install a manual shut off valve in the hose until you get your vaccum fiqured out ,or run a vaccum hose from a known vaccum on your engine to your shut off valve. This will keep your heat off for the summer.

 

[clar2001]

My heater hoses were disconected and once the car warmed up I still got hot air in the car thure the dash and vents ,
The seal around the bottom of the firewall were the hoses hooked up was damaged and missing. were the fender meets the fender well a seal there was broken.also a possibilty the door in the heater core /fan box is not closing all the way allowing engine heat to enter were the heater hoses hook up, jack up the car and look at this area from under neeth and you will see what I mean.

 

[Buckskin7T7V]

John 1977, I did block off the water control valve.

clar2001, this sounds like a possibility. On with the old clothes and under the car I go. This hot air thing, makes the car undrivable.

Thanks I will post my find.

 

[john1977]

But if the vaccum is not comeing out of your ac/heat/vent control to open and close your vent doors/defrost/ac/ you will get warm air. Can you hear the doors open and close when you change the positions on your control?

 

[clar2001]

I could here the doors close every time but the hot engine air still got in thure broken seals....

 

[Buckskin7T7V]

I took the resister that sticks down into the duct out. (Under the hood, on top of duct. It has a four or five wire connection to it) I could see that the flap door was saying open about a quarter of an inch with the temp control lever in the cold position. This also shuts off the heat water control valve. I tie wrapped this to the full closed position. The door seems sealed. I also to a florescent tube light and put it in the duct. (Where I took out the resister probe) With the garage lights out, I did see one hole that the light showed through. I installed a screw with sealant around it. I also went around every ducting to firewall connection with sealant. The vacuum door in the passenger kick panel opens only in the MAX position. I know this reticulates the air in the passenger compartment. Would I be better off blocking this door so that I only have inside air being reticulating and not outside air coming in? I am allowing the sealant dry over night and I will get back to you guys tomorrow. Thanks for the input and if you can think of more, please send them in.

 

[1981]

Sounds like you have gone futher than what I have done to a similar problem I am having. I just disconnected the power to the heater blower and "whala", no more heat blowing during the dead of summer. My entire A/C system is taken out of the car. I have all of the parts, but I will be replacing the compressor soon. I have a new condensor too. Since summer will be ending in a few months I will complete this project before next summer and hopefully have some cold air then.

Good luck, sound like you are getting closer to the problem.

1981

 

[Bob Chadwick]

This web page has a whole bunch of information on how the system works and suggestions on how to get a cooler interior.