What Does This Hook Up Too?

[slepr1]

In my search to find out why my 77 Cordoba heater fan doesn't produce very much air speed in any speed setting, I discovered a small diameter hose not attached to anything. The attached pictures shows the mystery hose. One is the starting point of the mystery hose under the dash. The other picture is where the mystery hose exits the firewall. Notice the hose shares the firewall exit point with the heater cable.

I don't know where that hose is suppose to hook up to. I presume it has something to do with the heater control push buttons that switches from defrost to vent, floor, ect, which doesn't work.

I installed a new heater fan motor so that is working. But when I switch the fan speed from low to high, their is no difference in fan motor noise. Any help would be appreciated.

 

[bm02tj]

You have a bad rheostat(resistor) or heater switch check with a voltmeter

 

[silversedan]

also make sure your fan motor is turning in the correct direction , if the leads are reversed it'll sound like it 's working but it will be trying to blow the air out of the car instead of in it.

 

[383man]

That looks like the hose that goes to intake manifold vacum. That white valve is a check valve to hold vacum in the system when you step on the gas and vacum drops. Get that hooked to intake vacum and the heat/ac doors should then work. With that hose off it has no vacum to the heat/ac head switch and with no vacum there it goes into the no vacum default position which mean all the air should come out the defrost only. The engineers figured if you lost vacum the most important position is defrost so in the winter it will heat the windshield so you can drive. You can get by without the other positions but you may be hot or cold. But keeping the windshield clean of ice is the most important position they feel so thats why cars go to the defrost mode if they loose vacum to the heat/ac head. Ron

 

[moparmarks]

Yep, for the heater control. And yep, defrost is the default mode. The little white thing is a check valve. One way valve so the control doesn't lose vacuum during acceleration.

 

[slepr1]

That's good to know. Now I have to find a barb small enough to fit that tiny hose. Thanks for the help fellas.

 

[Sixpactogo]

That vacuum hose must have been hooked up to the vacuum tee in the intake before. Check the vacuum tee and you should find an empty one. Once you get vacuum to your controls, everything should work properly. If you still don't have blower motor speed change when you switch it, you may have a bad connection at the blower motor resistor or possibly a bad resistor. Good luck

 

[razreddobie]

That's all Greek to me cause my Cordoba didn't come with air but sounds like the group put you in the right direction. Good luck.

 

[383man]

That's good to know. Now I have to find a barb small enough to fit that tiny hose. Thanks for the help fellas.

Usually there is a metal vacum nipple screwed into the intake on the backside of it or near there. It will have big nipple that may fit a 3/8 hose and then a small one also coming off it that is small enough to fit the vacum hose for the heat/ac system. Ron

 

[themechanic]

That thing-a-ma-bob goes into the cabin and connects to the flux capacitor.

 

[slepr1]

The connection on the intake is long gone. I have a M1 intake now. I think I'm looking for a Heater Vacuum Actuator. I just bought a 1977 Service manual but so far I can't find it anywhere. My search continues.

 

[slepr1]

I think I'll be looking for a intake vacuum tee...not a actuator.

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I think I'll be looking for a intake vacuum tee....not a actuator
.

- - - Updated - - -

I think I'll be looking for a intake vacuum tee....not a actuator
.

- - - Updated - - -

I think I'll be looking for a intake vacuum tee....not a actuator
.

- - - Updated - - -

I think I'll be looking for a intake vacuum tee....not a actuator
.

- - - Updated - - -

I think I'll be looking for a intake vacuum tee....not a actuator
.

- - - Updated - - -

I think I'll be looking for a intake vacuum tee....not a actuator

- - - Updated - - -

Sorry for that last 7x repeat post. Edit post didn't work and post didn't show up.

 

[Sixpactogo]

If you didn't toss your old intake, the tee is probably still on it. If not I have one with a few extra ports that you would need to plug. Here is a pic

 

[moparmarks]

Can just get a brass one from your local parts house. 3/8" pipe by 3/16" hose. Your M1 should have a threaded boss.

 

[Kernel Sanders]

Here is the setup I grabbed off a 75 Charger BB at the pick and pull for my 74 Charger and a picture of the underdash routing for the stratovent from my manual