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TR6 1974 TR6 heater hoses to firewall or bulkhead.


Luke Skywalker
Country flag
Bought '74 TR6. Heater was bypassed. I flushed out the
heater core and hooked up the hoses the way I thought
they should go. Fired her up and heater core and hoses
in passenger area get hot, but she still blows cool

I suspect hoses may be incorrectly connected. Can anybody
out there help by describing a proper connection at the
firewall or ... whatever? Thanks.


Jedi Trainee
Country flag
If the heater core gets hot, you must have gotten it right. The hot air should come out the bottom of the heater or the winshield defrost vents, depending on the position of the door at the bottom of the heater box. The dash vents always blow ambient air (as far as I know), and should be closed to get maximum airflow across the heater core.

74 TR6 CF13816U


Hmmmm. You have heat to the box, and yet nothing comes out. Sounds suspiciously like some little critter has built a home up in you heater box and you just installed central air and heat for her.
If you have heat there, do you actually hear the fan motor turning? Both speeds? You can turn your engine off and with the ignition on activate the fan motor. Take your grill off your air intake and look inside with a strong flashlight and small mirror (kinda like a dentist does) and see if there are any tell-tale pieces of debris inside the air intake.


Great Pumpkin
Here's the heater case that Bill's talking about. Of course, it's much easier done on the bench than in the car, so be sure before you start to take anything apart.


Good luck,


Jedi Warrior
that sounds strange. With hot water passing thru the heater core, you should be getting some hot air thru the air vents.
Even though the hoses are hot, your core could still be blocked. It maybe a good idea to get the heater box out and get the core pressure flushed.
Mine was chocked with a fine silt like mud. It took forever to get it all out.


Luke Skywalker
Country flag
Thanks for the reply, Tropic. Your comments have been
born out by my personal experience. Lower end of heater
box and dash vents are blowing cool air; but, I have
made strides by fiddling with the flapper door in the
heater box. I think this is my problem because the throw
on the knob from the dash is not what it should be. Maybe
a new cable or flapper door adjustment or replacement.

Also, Tec from Moss Motors says he doesn't think it matters
which way the water comes in or goes out, just so long as
it does. Seems like this is happening so I'll focus on
the knob to adjust from demisters on the windshield to the
cab of the car air flow via the flapper door in the
heater box. I'm trying like the dickens not to have to
remove this booger.


Luke Skywalker
Country flag
Thanks, Craig. This whole thing started when the previous
owner about a year ago disconnected the inflow and outflow
hoses on the bulkhead. Before I hooked anything up, I flushed with clear water from a garden hose through the
heater core. I was delighted when the water ran very
clear very soon. I'm hoping she is as good as she looks.
I think the problem is in the cable or flapper door on the
heater box that changes princple air from the cab of the
car to the windshield (defroster).

Got the heat to the defroster, now if I can only acheive the

I'll let you know how it goes, if you have any interest.


Great Pumpkin
Country flag
If you have heat to the top there has got to be heat available to the bottom. My guess is that the cable is bent and won't change locations.


Luke Skywalker
Country flag
Paul, I feel as if I already know you. Thanks for the reply
and I must tell you how much I appreciate all of those
wonderful pictures and helpful information you posted at
your web site. I see it as a very selfless act; but, as
I looked on with much appreciation, I was anticipating
with some degree of regret that I may have to expel the
unit from my car and perform similar surgery.

For me, this would be a last resort because my prowess
for mechanics is not so great, but by sheer determination,
sweat of brow and a few scraped knuckles, I seem to make

Must say thank you to you and those who take the time to
assist. I am following your web site and refurbishment.
Please let me know when you move to the next level. I want
to record the info on who you use to refurbish parts in case I have to face it down and pull that baby out.



Luke Skywalker
Country flag
Thanks, Bill. Yeah, I am very, very fortunate to have
the heater fan running (and both speeds at that). I think
it is the flapper door in the heater box that's the problem,
along with the cable going to it of course.

Something about the way this car has been kept makes me be
less critter-concerned, but hey...

If this flapper door thing isn't it, I'll look your note
up again. No offense, but I'm not quite sure where you
want me to look with this flashlight.

If there is a critter in there, he/she is really
toasty warm, at least for a while I'm driving.

Thanks again... hear you on the forum.


Great Pumpkin
Dennis, I'm glad that the pictures on my site put the case in a better perspective for you. It is hard to see in there and if it saves you or anyone time and labor, it's worth it.

Here are some additional pictures after I partially reassembled the box to try to help you out a bit more:

This is about all that the heater door will open on the bottom due to the fact that the arm hits the bracket on the case. Note the tube outlet to the right, above the bracket. This one and it's mate on the opposite side, go to the defroster and upper vents. I'll refer to it again a bit later.

heater 036 (Medium).jpg

This is a view looking down into the empty case. The core is at the bottom (shown in the next picture) and the motor and fan fill a lot of the space above it. The two side exit tubes provide air to the defroster and upper vents. If a critter got in there, he would have probably blocked of those as well, because there's not much room in there, but anything is possible.

heater 035 (Medium).jpg

Let's assume that he did and it's covering the core on top as shown here, then no air will get out of the bottom.

heater 014 (Custom).jpg

Lastly, this is looking at the opened door at the bottom where it would heat your feet. You could try to take the air hoses of of the sides of the case and blow compressed air back up through the bottom to see if it dislodges and debris on top of the core and out the side air tubes. maybe you could even snake a small vacuum hose in there to pull it out, but be careful! The cores are copper and not very resilient to being pushed and poked.

heater 037 (Medium).jpg
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