Interior Heater/Defrost Duct

[dfrazz]

Hi Everyone,
My '71 Challenger is missing a part on the defrost duct under the dash that I am having a hard time finding. The best I can tell is that 2 parts are there already; from the defrost vents down and from the firewall out. The part that is missing is approx. 4-5" of duct that connects the two existing parts together. The ends of the existing duct are smooth so I don't think the missing part was cut or ripped out. Right now, when I drive the car a lot of hot air from the engine is blowing into the car and you are sweating in about 15-20 minutes. Any ideas for replacements or places to look would be greatly appreciated. Thanks.

 

[Avalanche]

I'm not too sure but I think the defrost duct sits on the heater box (nothing in between).

Maybe someone else will chime in.

 

[challenger6pak]

To start off, is this an a/c car?

 

[Mike73Dodge]

This is what my 73 Challenger no AC looks like.

 

[burdar]

That picture is correct for a NON A/C car. There is supposed to be an open area between the heater box and the duct. It looks like something is supposed to be there but there isn't.

 

[moparleo]

Is your heater control valve working ? This cuts off the hot water to the heater so the interior will not heat up.

 

[burdar]

Those valves are only used on A/C cars. We don't know what he has yet though. If it's an A/C car then that's a good place to look.

Has your heater box been rebuilt? If not, all the foam pieces on the doors have deteriorated...probably not even there any more. That will let hot air past the doors even if they are closed. Also, a place to look for excessive engine heat in the interior is the lower steering column shaft seal. If the seal is missing(probably deteriorated just like the heater box foams) that will let engine heat enter the steering column and heat up the interior.

 

[dfrazz]

Update, it is an a/c car and the heater control is not working. I found the correct defrost part and installed it. Next step is to fix/replace the heater control as there is still heat coming in. Thanks Burdar, I will also look for the seal and foam pieces.

 

[moparleo]

The heater control valve should be mounted on the passenger side inner fender.

 

[dfrazz]

I also need to look at the cable to the actual dash control as the heat lever is stuck.