Another Heat In The Cockpit Question

[Bill75]

I've replaced every gasket, vent door gasket, and hood gasket that I could find and put a shutoff on the hot water feed to the heater core. Yesterday we drove to the shore and the heat was pouring from the heater all day. It's only happening when the car is in motion so there must be a vent door open or leaking somewhere. I've double checked the heater controls on the console and they appear to mbe to be working according to the vacuume schematic in the book.

Today I was poking around and found what looks like a vacuum actuater up high under the right front fender. It's just behind the screen in the fresh air inlet. I worked the heater/air conditioning controls to all possible positions and didn't see the actuator move at all. I removed the vacuum line to it with the engine running and found vacuum present on the line, and no movement of the actuator when I did so. When I changed the heater/air conditioning controls the vacuum on the line changed which would indicate the controls are functioning properly.

It kind of looks like this actuator might be the culpret but it's hard to see what it's supposed to be doing.

Attached is a schematic of the heater controls. Is this what could be causing the air flow in the heater and getting into the cab??

Bill

 

[Bob Chadwick]

This actuator is part of the controls for the a/c high/recirculation mode. It is one of the two controls that determine whether you get fresh air or recirculated air in the car. Explanation can be found on my web site.

Mine is greatly improved though over the course of the day I can feel the heat coming out of the vents creeping up. I need to get it on the ramps and play around with some of possible heat sources under the a/c box.

 

[mrvette]

Well, obviously you found the source of your troubles, I just pull the vent flapper and controller, and disable the thing, seal it shut with RTV rubber and forget about it, then pull the flapper under the kickplate inside....this makes the car in permanent recirc/max air mode.....course I have a convertible, so i'ts not so bad for me....

I feel these cars have enough in the way of air leaks that permanent recirc is the desired mode of operation.....that and insulate the hell out of the floorboards...

GENE

 

[Bill75]

Well, I pulled the thing out and learned a few things besides what you guys mentioned.
First, this thing has never ever worked because the guy who installed it at the factory pinched the vacuum line under the mounting plate behind the door. You couldn't see it until it was removed. See Pic.
Second, there was a bead of epoxy left from assembling the body, under the flange which prevented it from seating flush and thereby prevented the door from operating properly.

I replaced the vacuum line and ground away the epoxy with a Dremmel tool and it works perfectly now.

Bob, I read that Info on your site and it never hit me that there were two actuators on the vent.

Gene, I see where you're coming from after I figured this thing out. There's really no need for that door to be open; who needs hot fresh air and if the AC is on, it'll be in Max anyway which would close the door I believe.

So now another question..It seems to me that the rainwater would flow right into this opening. I also saw a small passageway behind where the door seals that I assume is a water passage if the door is closed. That passage still leads into the same duct as the fresh air so even if the door is closed, fresh air goes in thru the water passage.

Am I seeing this correctly????

Bill

 

[Bob Chadwick]

There is a drain on the bottom. If you take out the lower actuator and place a shop light in the space you will see the light coming out under the car. That is the area that they talk about placing some straws in the hole, sealing up around them and then pulling out the straws to make the holes smaller.

 

[Glen Braxton]

Air is allowed to pass through the heater core by a door, which is controlled by a cable that attaches to the right hand thumb wheel on your console control.
Heat coming in means the door is not sealing. So either you have a bad seal, or more likely your control cable is not adjusted properly, disconnected or is broke!

 

[Bill75]

OK on the straws Bob, it's just strange that they put a door there that seals, then put a drain hole for water right next to it that lets the air back in the ductwork. But as you pointed out Glen, the door that seals the air from getting at the heat exchanger must be he real culpret. I think that's a job for another day, looks like I'll have to take the dash out again to get at it. Yucckkkk!

Thanks for all the help. If I get some ambition later I'll see what's up with the door.

Bill

 

[Bob Chadwick]

Dash doesn't need to come out to get to the bottom door. Remove the sill and a couple of screws in the kick panel and its out.

 

[Bill75]

Bob,

That door behind the kick panel isn't controled by the temp knob on the console. That's a vacuum operated door that allows fresh air directly in the cab if the top door is open (the one I found not working).
Isn't the one Glen is talking about located in the duct behind the center portion?? It's attached to the cold/hot temp by means of a cable.

 

[Bob Chadwick]

Bill,

I thought you were talking about the actuator that controls the recirculation/fresh air function. I misunderstood.

The turnbuckle that adjusts the door you are talking about can be accessed on my car by removing the passenger side tunnel cover.

However, you indicate you have placed a mechanical valve in line. If it is closed, no hot water is getting to the core so no adjustment will have an impact on it.

Bob

 

[Bill75]

OK Bob, thanks. It takes quite a while for the hot air to start coming thru. I think even though the valve is closed the water gradually heats up from the heat of the engine. I think I'll have to locate that other door that Glen mentioned. I can feel a slight airflow coming from the heater vents, so air must be getting to the heater core somehow.

Bill