Fresh air door

[nick]

I traced an annoying squeek to a hinged door that can be accessed by opening the hood and reaching back through the cold air plenum. I is directly under the center removable grill on top of the dashboard. On my car this door swings freely as though it is not connected to anything. I suspect it should be connected to one of the heater control levers. Anyone know how this is suppose to work?

nick

[Hasbeen]

Nick, the inner right hand heater control lever [the fan one] is the
one that controls that flap.

A heavy wire rod connects the leaver to a shaft comming out of the
heater unit. The rod connects to the shaft with a bell crank, that
just pushes onto the shaft. I have had the bell crank fall off the
shaft a number of times on various 7s.

Make sure you have the flap & control lever both, in the correct
place, before you slide the bell crank on to the shaft. Although
they fall off, it is very difficult, [in the confined space under
the dash], to get back off, ouce you've put it on in the wrong place.

I hope you enjoy your time down under the dash. I find it a right
pain in the backside.

Hasbeen

[nick]

Thanks Hasbeen,
The fan control on my car is marked off at the top and then 1 thru 3 or 4 at the bottom representing the fan speeds. I don't understand why the fan control operates this door. I would expect this door to be operated by the hot/cold lever in order to mix cold air to the heated air for temperature control. Could you explain further how this works?

nick

[Hasbeen]

Nick, there is no hot air, [unless you remove the plenum]. The door
you are talking about either admits or excludes outside air.

That door you open with that control leaver admits outside fresh
air, via your fresh air plenum. When you want hot air, the cooling
water is used to heat this air. The same air is used as cooling air,
when you have the heat off.

I can only assume they use the same leaver to control the
ventilation air supply, & the fan motor as it would be pointless,
& probably damaging to run the fan motor, with no air supply, for
the fan to blow. This system makes that impossable, if every thing
is connected.

It is a bit hard to explain, although I could show you in a second.
I expect when you have a good look under the dash, it will all be
revealed.

Hasbeen

[jclay (RIP 2018)]

There is a whole set of instructions on setting those controls in the ROM.

[url="http://homepage.mac.com/WebObjects/FileSharing.woa/34/wo/WNaXHpymN5Mka43u.1/0.2.1.2.26.31.97.1.35.0.1.1.1?user=jclaythompson&fpath=Triumph_Articals&templatefn=FileSharing4.html"]Follow this link, download the TR7man.pdf and look under Air Conditioning.[/url]



Have fun, drive fast & safe, be kewl,

jclay

[nick]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Hasbeen</i>

Nick, there is no hot air, [unless you remove the plenum]. The door
you are talking about either admits or excludes outside air.

That door you open with that control leaver admits outside fresh
air, via your fresh air plenum. When you want hot air, the cooling
water is used to heat this air. The same air is used as cooling air,
when you have the heat off.

I can only assume they use the same leaver to control the
ventilation air supply, & the fan motor as it would be pointless,
& probably damaging to run the fan motor, with no air supply, for
the fan to blow. This system makes that impossable, if every thing
is connected.

It is a bit hard to explain, although I could show you in a second.
I expect when you have a good look under the dash, it will all be
revealed.

Hasbeen


<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
I guess I thought that the hot water heats the air but then if you do not want the maximum temperature you add cooler outside air. On my Toyota I have an electrical fan switch, a lever that is recirc/outside air, and a temp control. On the wedge, I guess the fan and outside air are on the same lever but unlike the Toyota the fan can not be activated without opening the outside air source.

nick

[rsamis]

The damper rod connected to the fan switch struck me as an odd arrangement too. Something's not right on my car, because the linkage prevents the fan switch from moving all the way down into the highest speed setting. The switch is also unable to slide all the way to the top of its slot, although that's just a cosmetic thing.
Hasbeen, is this what happens when the linkage is assembled incorrectly?

Royal
76 FHC, 4-spd, dual Strombergs

[Hasbeen]

Royal, there must be some other problem with your control leaver.
What normaly happens is you get full travel one way, but the flap,
[door] comes up against its stop, before the leaver reaches full
travel the other way. This is probably what's stopping yours
reaching the top of its slot.

Its not too hard to get the rod off the control leaver. With that
off you should be able to trace any restrictions to its movement.

At this end you can't get the instillation wrong.

Hasbeen

[jclay (RIP 2018)]

When you put the fan control on MAX, you are recycling the air in the car, as long as you don't open the vent control. As you slide the fan control lever down towards the "3" fan speed, you let more out side air into the system.

Have fun, drive fast & safe, be kewl,

jclay

[nick]

Hasbeen, how do you access this shaft? Is it from the passanger side on left hand drive cars? What needs to be disassembled? I looked under the dash on both sides but can not see the controls.

[quote]<i>Originally posted by Hasbeen</i>

Nick, the inner right hand heater control lever [the fan one] is the
one that controls that flap.

A heavy wire rod connects the leaver to a shaft comming out of the
heater unit. The rod connects to the shaft with a bell crank, that
just pushes onto the shaft. I have had the bell crank fall off the
shaft a number of times on various 7s.

Make sure you have the flap & control lever both, in the correct
place, before you slide the bell crank on to the shaft. Although
they fall off, it is very difficult, [in the confined space under
the dash], to get back off, ouce you've put it on in the wrong place.

I hope you enjoy your time down under the dash. I find it a right
pain in the backside.

Hasbeen

<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

nick

[Hasbeen]

Nick, its on the same side as the fan speed control lever.
Look just behind the dash, at the inboard end of the lever
that controls the fan speed. There should be a rod from that,
outside the heater box, to a shaft coming out of the heater box, at
the front, close to the fire wall.

If there is no rod, connected, or hanging from one place or other,
it may have been lost by a previous owner. If that's the case you'll
have to find a second hand bit from somewhere. Yoke may have one, as
he's parted a few cars.

If all else fails, use a self tapping screw to fix it to the frame
behind it, [open] for summer, & to the fire wall, [closed] for
winter.

Hasbeen