Need Help on Final Check for PV at Florida Reginal

[Bob P.]

I went through everything on my '66 a final time in preparation for my PV for next weeks Florida Regional and have a couple of questions on the function of heater and fan control.

The PV manual and the owners manual both state that the "AIR-PULL-DEF" knob is the air "on and off" control. Doesn't this knob just control the distribution of air between the floor duct at the rear of the console and the defroster. It doesn't really have anything to do with the air being on or off does it?

When and how should air come out of the sides ducts that are on the side of the console?

The manual also talks about that the "AIR-PULL-DEF" knob must be pulled to the detent position or further before the heater will operate. Does that mean that the fan will not operate with this knob in the fully closed position? What happens when this knob is fully closed and the fan is on? Do you not get any air flow and if you do where should the air come out at?

I also can't feel a really defined "detent". Is this common? How far out do you have to pull the knob to feel the detent?

The "FAN-TEMP-PULL" knob does nothing more than control fan speed and air temp, correct?

Thanks for your help.

[John H.]

Re: Need Help on Final Check for PV at Florida Reginal

I went through everything on my '66 a final time in preparation for my PV for next weeks Florida Regional and have a couple of questions on the function of heater and fan control.

The PV manual and the owners manual both state that the "AIR-PULL-DEF" knob is the air "on and off" control. Doesn't this knob just control the distribution of air between the floor duct at the rear of the console and the defroster. It doesn't really have anything to do with the air being on or off does it?

When and how should air come out of the sides ducts that are on the side of the console?

The manual also talks about that the "AIR-PULL-DEF" knob must be pulled to the detent position or further before the heater will operate. Does that mean that the fan will not operate with this knob in the fully closed position? What happens when this knob is fully closed and the fan is on? Do you not get any air flow and if you do where should the air come out at?

I also can't feel a really defined "detent". Is this common? How far out do you have to pull the knob to feel the detent?

The "FAN-TEMP-PULL" knob does nothing more than control fan speed and air temp, correct?

Thanks for your help.

Bob -

The Fan-Temp knob regulates heater output temperature and controls the fan speed. The Air-Def knob controls the airflow - the first half of knob travel opens the air door allowing airflow from the heater to exit through the floor distributor openings, and the second half of travel opens the defroster door, diverting that airflow to the defroster duct openings.

There's an excellent explanation of heater control functions and a diagram of heater airflow in the heater on page 1A-3 in the Chassis Service Manual.

[Bob P.]

Re: Need Help on Final Check for PV at Florida Reginal

John,

Thanks for the help! Unfortunately I don't have a Chassis Service Manual. What you described is how I understood it to work.

Should air flow through the console sides when the AIR DEF knob is blowing air to the floor or is there a different setting for that?

Is there a definite detent that can be felt when the knob is pulled out s certain distance?

I believe I have the system set up right, but not sure. Anyway you can send me the diagram from the Chassis Service Manual?

[John H.]

Re: Need Help on Final Check for PV at Florida Reginal

John,

Thanks for the help! Unfortunately I don't have a Chassis Service Manual. What you described is how I understood it to work.

Should air flow through the console sides when the AIR DEF knob is blowing air to the floor or is there a different setting for that?

Is there a definite detent that can be felt when the knob is pulled out s certain distance?

I believe I have the system set up right, but not sure. Anyway you can send me the diagram from the Chassis Service Manual?

Bob -

The console sides and the floor are the same airflow path - the only other path is the defrosters. When the car was new, there was a discernible detent where the knob started to divert airflow to the defrosters. The heater flow diagram is below - also see your owner's manual, page 20.


HeaterAirflow800.jpg

[Bob P.]

Re: Need Help on Final Check for PV at Florida Reginal

John, Again thanks for your help. As you can imagine I'm "cramming" trying to make sure everything is ready for the PV later this week. Based on the diagram it appears that the defrost door is tied to the "AIR - DEF" knob and it controls the flow of air to the defroster or floor. The heat door is tied to the "FAN - TEMP" knob and controls temperature. I'm not sure how the air door is controlled/activated? I assume that it is tied to the "AIR - DEF" knob? It appears that if the air door is closed and the fan was on, there wouldn't be any flow at all and you can control the amount of flow with this door regardless of fan speed? My "AIR-DEF" knob will not do this.

[Richard M.]

Re: Need Help on Final Check for PV at Florida Reginal

Here are some photos of a '67 box. I believe similar to '66 in it's design and mechanical actuation. Maybe some of this can help answer your questions. John or anybody chime in if I'm wrong as it's a little foggy. All from memory.

A few reference photos to start....

Main control box.
P2240051.jpg

Defrost outlet. The Defrost Door can be seen. Also note the internal mechanism.
IIRC, that is where a flat spring and cam is installed. I think this is where the "Detent" happens.
I don't think it's in the cable. When the door moves through it's travel, the spring reaches a
"overcenter" point and helps flip the door over. I only remember this from when I rebuilt this box
a few years ago.
P2240052.jpg

This is the defroster "funnel". Note it's not designed to fit tight against the oval port above.
It sits just above it as it's mounted to the upper dash, not the box. Most of these break during
box repairs as the fiberglass is very thin. I worked on this one.
P2240062.jpgP2250030.jpgP2250031.jpg

Core inlet, notice the opening next to it to bypass heated air into the box.
P2240053.jpg

Core removed, showing HEAT door.

P2240056.jpg

Floor diverter. I think this may be different on a '66. Reason being in '67 the kick panel vents
were cable controlled at the sides of the radio console. '66 has knobs underdash for that and
there are air outlets on the sides of the radio console panels. .......IIRC?
P2250027.jpgP2250028.jpg

This is where the core resides. You can see the "HEAT" door in the hole. This was after installing a "re-seal" kit.
P3010013.jpg


Here you can see one of the mechanisms. IIRC the AIR/DEF cable goes to the link pin shown on the circular cam linkage.
That controls the Defroster Door, but the lever attached to that cam also controls the AIR door. When this contraption moves through it motion, there is a detent, or a noticeable resistance in it as it switches over.

I don't have a photo of it, but I'm recollecting the flat spring inside this mechanism is where the detent is felt. This box had a broken spring. After repairing it(with silver solder), I recalled a noticeable "detent" through its motion.
P3010014.jpg

Air Door inside box
P3010015.jpg


Here is the mechanism for the HEAT function. I believe this one also has a dual purpose,
controlling the main input door and the internal AIR door. The mechanism is adjustable
to get the internal seals tight as I recall.
P3010012.jpg


Reinstalled with cables attached.
P3010021.jpgP3010022.jpgP3010023.jpgP3010024.jpgp3010025.jpg


==========

[Bob P.]

Re: Need Help on Final Check for PV at Florida Reginal

WOW Thanks for the help.

Of course I have a few additional questions. The cam mechanism with the flat spring, is the spring internal or external to the box? In other words, is the spring located below cam or is it inside the box. I'm just trying to see how much of this I need to tear apart to get to the spring, which I think would address one issue I have of no detent. Only one of these mechanisms looks like it has adjustment, that would be the HEAT mechanism and I assume you adjust it by loosing a screw at either end and rotate the mechanism? Not sure what that will do though?
Finally, it looks like I can get to this mechanism by removing the glove box, would you agree?

Thanks again for your help!

[Richard M.]

Re: Need Help on Final Check for PV at Florida Reginal

WOW Thanks for the help.

Of course I have a few additional questions. The cam mechanism with the flat spring, is the spring internal or external to the box? In other words, is the spring located below cam or is it inside the box. I'm just trying to see how much of this I need to tear apart to get to the spring, which I think would address one issue I have of no detent. Only one of these mechanisms looks like it has adjustment, that would be the HEAT mechanism and I assume you adjust it by loosing a screw at either end and rotate the mechanism? Not sure what that will do though?
Finally, it looks like I can get to this mechanism by removing the glove box, would you agree?

Thanks again for your help!

Bob, The flat spring is internal to the box. I didn't take photos when I had it apart. Memory tells me it's at the mechanism related to the AIR-DEF function, and as John explained above, is where the 2 functions are integrated. But maybe it's just the mechanism that created the detent, and the spring is there as a assist. I honestly forget and don't want to give you wrong info and make you do something you don't have to.

I think those adjustment screws and the oval slots are to get the seals tight, to compensate for variations in the mechanism, flapper doors, etc.

Yes, remove the glovebox and it's there, as shown in my last few photos above. Note I also had the console side panels out as I rebuilt the kickpanel vent doors at the same time.

If you get in there to access the box, I'd disconnect the cables and manually flip the levers to see if you can "feel" any detent at half travel. Also check the disconnected cable. I'm not sure if the cable has the function, seems possible, but unlikely IMO. ???

Did you rebuild the heater box with new seals? I don't know if the airflow is tested for leakage, but seal condition may be important.

Rich
p.s. I commend you for going for a PV. I hope it passes! I'll be there this week so I'll have to stop by for a visit.

[Richard M.]

Re: Need Help on Final Check for PV at Florida Reginal

Bob,

here are the 1967 pages from the CSM covering the heater. I suggest you get a copy of the 1966 CSM, but this may help for now.

Rich

P1190146.jpg

P1190147.jpgP1190148.jpgP1190149.jpg
P1190150.jpgP1190151.jpgP1190152.jpg

[Bob P.]

Re: Need Help on Final Check for PV at Florida Reginal

Rich,

Thanks so much for your help. I have it operating correctly or at least in my opinion it operates correctly. It actually just took some adjustment of the cable from the Air Defrost knob at the heater box! I'll see what happens during the PV.

[Richard M.]

Re: Need Help on Final Check for PV at Florida Reginal

'yur welcome. I hope you get it. Good Luck.

I'll have to stop by and check out your car. Sounds very nice.

Rich

[John H.]

Re: Need Help on Final Check for PV at Florida Reginal

Bob -

Here are a couple of .pdf's from Dave Zuberer that explain how the internal "detent" mechanisms work and how the various doors and seals operate.


HeaterBoxDoorPositions.pdfHeaterBoxDoor.pdf