New 1976 Owner with Limited Skills

Group - I just bought my first Corvette -1976. I have no experience
with working on cars at all, but am a fast learner. I drove it home
last night and found out that the heat doesn't work. I'm not sure
where to begin to search for the problem. Is this something that I
can fix myself or should I take it to a mechanic?

For diagnostic purposes - the fan blower works and both dials on the
control panel move and air flows both at the top and bottom. I put it
on defrost, heater, and vent and had the same frigid results.

Any help will be appreciated...

"1976VetteGuy" > wrote in message
...
> Group - I just bought my first Corvette -1976. I have no
> experience
> with working on cars at all, but am a fast learner. I
> drove it home
> last night and found out that the heat doesn't work. I'm
> not sure
> where to begin to search for the problem. Is this
> something that I
> can fix myself or should I take it to a mechanic?
>
> For diagnostic purposes - the fan blower works and both
> dials on the
> control panel move and air flows both at the top and
> bottom. I put it
> on defrost, heater, and vent and had the same frigid
> results.
>
> Any help will be appreciated...

what about the temp slide bar ? Does it work ?
are you sure that the heater core has NOT been bypassed ?

--
'Key
=====

The temp slider does move, but I don't know if it's doing anything.
Is there an easy way for me to tell if it's actually moving the proper
door?

As far as the heater core being bypassed...I have no idea and don't
really even know what that means, so any enlightenment would be
helpfull!!!!

Thanks

--
'Key
=====

"1976VetteGuy" > wrote in message
...
> The temp slider does move, but I don't know if it's doing
> anything.
> Is there an easy way for me to tell if it's actually
> moving the proper
> door?

you should be able to hear it working the door. if the cable
is broken you should feel nearly no tension
on the slider and hear nothing.

> As far as the heater core being bypassed...I have no idea
> and don't
> really even know what that means, so any enlightenment
> would be
> helpfull!!!!
>
> Thanks

sometimes when a heater core goes bad (leaks) folks will
bypass the heater core.
you can look under your hood and see the heater hoses.
the heater core is located on the passenger side if your
car.
follow your heater hoses, from you water pump, and see if
they go directly in and out of the fire wall where the
heater core is located.
if the heater core was bypassed? you should see the bypass.

g'luck
--
'Key

Here's some diagrams that might help you understand what's in your car:
http://www.docrebuild.com/dr-r-web/AC-VAC2.PDF

Look at the diagram at the bottom center of the page and note the
unlabeled device at the top of the picture... that's a metal diverter valve
that sits in the engine compartment and has heater hoses connected to it.
The heater hoses are attached to the nipples shown at the top and right
coming out of that valve, the small hose shown as white in the diagram is a
vacuum hose that actuates the diverter valve to send hot water through
to the
heater core under the dash when you turn on the heater, or to bypass the
heater core and send the hot water back to the engine.

note: This particular picture shows a system without a/c, but I believe
that same
valve is present on cars that DO have a/c as well, but they just don't
show it
on the a/c diagram (upper left on the page), they only show the airflow
door actuators.
I don't have a C3, so I can't verify that.

That valve can stick or become disconnected from the vacuum hose, or
there could
be a leak in the vacuum system that prevents sufficient vacuum from
reaching the valve.
It is a common point of failure. The valve is not particularly expensive
to replace.

It could be checked by applying vacuum directly to the valve to see if
the heater
then works (you should be able to feel that the water hose from the
diverter
to the heater is cool before vacuum is applied, then heats up with
vacuum applied).
You may need a vacuum pump to test with, or you can "borrow" vacuum from
another vacuum source on the engine by "Tee"ing into that good vacuum
source.
(Simply sucking on the hose orally is not likely to produce sufficient
vacuum.)

You could also disconnect the two water hoses from the diverter valve
and clamp
them to opposite ends of one short section of copper tubing (5/8" I
believe) to bypass
the valve for the winter, then reattach them to the diverter valve in
the spring.

Good luck.

Well, I may have lied a bit...after some reflection, I think what I called
the "diverter" valve simply stops water from passing through to the heater,
rather than diverting it back to the engine.

WayneC wrote:
> Here's some diagrams that might help you understand what's in your car:
> http://www.docrebuild.com/dr-r-web/AC-VAC2.PDF
>
> Look at the diagram at the bottom center of the page and note the
> unlabeled device at the top of the picture... that's a metal diverter valve
> that sits in the engine compartment and has heater hoses connected to it.
> The heater hoses are attached to the nipples shown at the top and right
> coming out of that valve, the small hose shown as white in the diagram is a
> vacuum hose that actuates the diverter valve to send hot water through
> to the
> heater core under the dash when you turn on the heater, or to bypass the
> heater core and send the hot water back to the engine.
>
> note: This particular picture shows a system without a/c, but I believe
> that same
> valve is present on cars that DO have a/c as well, but they just don't
> show it
> on the a/c diagram (upper left on the page), they only show the airflow
> door actuators.
> I don't have a C3, so I can't verify that.
>
> That valve can stick or become disconnected from the vacuum hose, or
> there could
> be a leak in the vacuum system that prevents sufficient vacuum from
> reaching the valve.
> It is a common point of failure. The valve is not particularly expensive
> to replace.
>
> It could be checked by applying vacuum directly to the valve to see if
> the heater
> then works (you should be able to feel that the water hose from the
> diverter
> to the heater is cool before vacuum is applied, then heats up with
> vacuum applied).
> You may need a vacuum pump to test with, or you can "borrow" vacuum from
> another vacuum source on the engine by "Tee"ing into that good vacuum
> source.
> (Simply sucking on the hose orally is not likely to produce sufficient
> vacuum.)
>
> You could also disconnect the two water hoses from the diverter valve
> and clamp
> them to opposite ends of one short section of copper tubing (5/8" I
> believe) to bypass
> the valve for the winter, then reattach them to the diverter valve in
> the spring.
>
> Good luck.

On Nov 27, 4:39 am, WayneC > wrote:
> Here's some diagrams that might help you understand what's in your car:
> http://www.docrebuild.com/dr-r-web/AC-VAC2.PDF
>
> Look at the diagram at the bottom center of the page and note the
> unlabeled device at the top of the picture... that's a metal diverter valve
> that sits in the engine compartment and has heater hoses connected to it.
> The heater hoses are attached to the nipples shown at the top and right
> coming out of that valve, the small hose shown as white in the diagram is a
> vacuum hose that actuates the diverter valve to send hot water through
> to the
> heater core under the dash when you turn on the heater, or to bypass the
> heater core and send the hot water back to the engine.
>
> note: This particular picture shows a system without a/c, but I believe
> that same
> valve is present on cars that DO have a/c as well, but they just don't
> show it
> on the a/c diagram (upper left on the page), they only show the airflow
> door actuators.
> I don't have a C3, so I can't verify that.
>
> That valve can stick or become disconnected from the vacuum hose, or
> there could
> be a leak in the vacuum system that prevents sufficient vacuum from
> reaching the valve.
> It is a common point of failure. The valve is not particularly expensive
> to replace.
>
> It could be checked by applying vacuum directly to the valve to see if
> the heater
> then works (you should be able to feel that the water hose from the
> diverter
> to the heater is cool before vacuum is applied, then heats up with
> vacuum applied).
> You may need a vacuum pump to test with, or you can "borrow" vacuum from
> another vacuum source on the engine by "Tee"ing into that good vacuum
> source.
> (Simply sucking on the hose orally is not likely to produce sufficient
> vacuum.)
>
> You could also disconnect the two water hoses from the diverter valve
> and clamp
> them to opposite ends of one short section of copper tubing (5/8" I
> believe) to bypass
> the valve for the winter, then reattach them to the diverter valve in
> the spring.
>
> Good luck.

wow...thanks for the detailed answer. I'll check that out tonight
when I get home...

On Nov 27, 4:39 am, WayneC > wrote:
> Here's some diagrams that might help you understand what's in your car:
> http://www.docrebuild.com/dr-r-web/AC-VAC2.PDF
>
> Look at the diagram at the bottom center of the page and note the
> unlabeled device at the top of the picture... that's a metal diverter valve
> that sits in the engine compartment and has heater hoses connected to it.
> The heater hoses are attached to the nipples shown at the top and right
> coming out of that valve, the small hose shown as white in the diagram is a
> vacuum hose that actuates the diverter valve to send hot water through
> to the
> heater core under the dash when you turn on the heater, or to bypass the
> heater core and send the hot water back to the engine.
>
> note: This particular picture shows a system without a/c, but I believe
> that same
> valve is present on cars that DO have a/c as well, but they just don't
> show it
> on the a/c diagram (upper left on the page), they only show the airflow
> door actuators.
> I don't have a C3, so I can't verify that.
>
> That valve can stick or become disconnected from the vacuum hose, or
> there could
> be a leak in the vacuum system that prevents sufficient vacuum from
> reaching the valve.
> It is a common point of failure. The valve is not particularly expensive
> to replace.
>
> It could be checked by applying vacuum directly to the valve to see if
> the heater
> then works (you should be able to feel that the water hose from the
> diverter
> to the heater is cool before vacuum is applied, then heats up with
> vacuum applied).
> You may need a vacuum pump to test with, or you can "borrow" vacuum from
> another vacuum source on the engine by "Tee"ing into that good vacuum
> source.
> (Simply sucking on the hose orally is not likely to produce sufficient
> vacuum.)
>
> You could also disconnect the two water hoses from the diverter valve
> and clamp
> them to opposite ends of one short section of copper tubing (5/8" I
> believe) to bypass
> the valve for the winter, then reattach them to the diverter valve in
> the spring.
>
> Good luck.

To all that helped me out I thank you...

So from reading past posts, I am going to install the manual valves on
the hoses as I think the vacuum control valve might be stuck in the
closed position or something as I am not getting any flow to the
heater core.

One last question to everyone about this...do I need to drain the
coolant level down to close off these valves in the summer? Also,
when they are shut off, how can I make sure the heater core is not
going to rust while it is not being used? In other words, do I drain
it somehow when I close off the manual valves? Or does the water just
stay in there all summer?

Thanks again!!!

On Nov 26, 3:23 pm, "'Key" > wrote:
> --
> 'Key
> =====
>
> "1976VetteGuy" > wrote in message
>
> ...
>
> > The temp slider does move, but I don't know if it's doing
> > anything.
> > Is there an easy way for me to tell if it's actually
> > moving the proper
> > door?
>
> you should be able to hear it working the door. if the cable
> is broken you should feel nearly no tension
> on the slider and hear nothing.
>
> > As far as the heater core being bypassed...I have no idea
> > and don't
> > really even know what that means, so any enlightenment
> > would be
> > helpfull!!!!
>
> > Thanks
>
> sometimes when a heater core goes bad (leaks) folks will
> bypass the heater core.
> you can look under your hood and see the heater hoses.
> the heater core is located on the passenger side if your
> car.
> follow your heater hoses, from you water pump, and see if
> they go directly in and out of the fire wall where the
> heater core is located.
> if the heater core was bypassed? you should see the bypass.
>
> g'luck
> --
> 'Key

Thanks...I don't think it was bypassed, but not sure. I actually
don't even know where the heater core is located...I assume it's
behind the firewall??? So if you have the time, can you get more
detailed and tell me how to check this as I have replaced the
thermostat and made sure it has enough coolant. I'm pretty sure it
either a hose or heater core problem of some sort. I wouldn't know
what the bypass would look like. I can't even find the damn water
pump. I bout a new one, but my future father-in-law says that I would
know if it was bad as it would be noisy and the car would overheat.
So I need to find that so I can follow the hoses to the heater core?
The guy at Autozone said that I should try to clean/flush out the
cooling system...to try to clean out any gunk or rust that may be in
there???? I bought a kit and a solvent to flush it with, but don't
want to go throughg the trouble if I don't have to....???? It would
be a cheap fix if it worked...

Is the heater core hard to get to???

Thanks for your help...

On Wed, 5 Dec 2007 22:04:38 UTC, 1976VetteGuy > wrote:

> Is the heater core hard to get to???

The other possible solutions are much easier to try. I've done the
heater coil, A/C, and pretty much everything else on my 1982. The
heater coil fits through the firewall. The first step in the
repair manual is to remove the seats, dash, and everything over
the interior part of the heater coil. The second step involves
removing the parts in the way under the hood. A good mechanic
will charge about $500-700 for the day it will take to replace it.
Start by finding a repair manual for your 1976.

David