no heat?
Thread Starter
Racer
Joined: Jul 2006
Posts: 499
Likes: 0
From: Colebrook Connecticut
no heat?
well I took the 69 vette out of the garage for the monthly warm up etc.
and had the heater crankin inside.
but no heat?
blowers working and all the plumbing is hooked up?
first time I tried the heater since i bought the car last october.
One thing i do know is the previous owner was messing around in the center console area and im thinking he wired something wrong on the controls.
and had the heater crankin inside.
but no heat?
blowers working and all the plumbing is hooked up?
first time I tried the heater since i bought the car last october.
One thing i do know is the previous owner was messing around in the center console area and im thinking he wired something wrong on the controls.
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How cold was it outside? Whenever I drive my cars this time of year they run so cold the car doesn't heat up. Since your heater is getting it's heat from a cool running engine it blows colder than normal air. Also you may have a faulty thermostat.
Thread Starter
Racer
Joined: Jul 2006
Posts: 499
Likes: 0
From: Colebrook Connecticut
car was fully warmed up to 190 degrees
A/c works at least in summer but it could be colder.
I tested the thermostat in boiling water and it works.
where is the blend door located?
is it electrical or vacum controlled?
if its a vacum controlled door that might explain why my wiper door creeps up a bit after I shut the car off.
A/c works at least in summer but it could be colder.
I tested the thermostat in boiling water and it works.
where is the blend door located?
is it electrical or vacum controlled?
if its a vacum controlled door that might explain why my wiper door creeps up a bit after I shut the car off.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
The coolant flow valve in the engine-side heater hose opens to allow flow into the heater core. It is vacuum-actuated via a small tube running from the console heater controls to the valve itself. It is likely that that tube is disconnected at the console. Or alternatively the valve is frozen/corroded shut internally.
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Team Owner
Joined: Aug 1999
Posts: 30,995
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From: Ontario
Vacuum checks/diagnoses can be frustrating. Another way to do it is to remove the valve and join the two cut ends of the hose with a short piece of pipe, clamp, and start engine. Without the valve in place there will be unrestricted flow towards/into the heater core and you should have heat. If not, then the core is plugged. If yes, then you can go looking for the vacuum leak or bad valve. On the latter, I believe places such as Autozone still can get access to them.
Pro
Joined: Jan 2006
Posts: 575
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From: Ventura California
Check the heater control valve. It is a vacuum operated switch that is in line with the 5/8" hose between the manifold and the heater core, in the engine compartment. Mine is actually mounted behid the right side louver just before the heater core.
Race Director
Joined: Jul 2002
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From: A 12/8 man in a 4/4 world
Instructor
Joined: Dec 2006
Posts: 116
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From: Crystal Lake Illinois
Make sure the hoses are connected correctly. Had a friend that went 2 winters with no heat, would get a little warm but never hot. Finally he figured he would look into it and he had the hoses reversed
Burning Brakes
Joined: Jun 2002
Posts: 837
Likes: 3
From: Texas
Here's a thread from the archives where the water inlet valve is being discussed.
http://forums.corvetteforum.com/show...+control+valve
http://forums.corvetteforum.com/show...+control+valve
Drifting
Joined: Mar 2006
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From: Oak Ridge NC
Race Director
Joined: Mar 2006
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From: Florida
After you have eliminated your valve as a problem:
You can just feel the two heater hoses, they should be almost the same temp-hot or check with an a/c vent thermometer held against them.
Then
You may want to check the coolant flow thru the heater core.
Disconnect the heater lines at the manifold and waterpump.
Connect a 4 ft long 5/8 heater hose to a garden hose and run into a 5 gal bucket noting the time it takes to fill.
Connect the garden hose to the 5/8 line of the heater core and put the 3/4 outlet line in bucket and time that one.
If the time is different the heater core is plugged and needs replaced. They cannot be flushed out properly.
It is a common problem.
Also a 195° thermostat is usually necessary for good heat.
You can just feel the two heater hoses, they should be almost the same temp-hot or check with an a/c vent thermometer held against them.
Then
You may want to check the coolant flow thru the heater core.
Disconnect the heater lines at the manifold and waterpump.
Connect a 4 ft long 5/8 heater hose to a garden hose and run into a 5 gal bucket noting the time it takes to fill.
Connect the garden hose to the 5/8 line of the heater core and put the 3/4 outlet line in bucket and time that one.
If the time is different the heater core is plugged and needs replaced. They cannot be flushed out properly.
It is a common problem.
Also a 195° thermostat is usually necessary for good heat.
Last edited by noonie; Feb 18, 2007 at 04:30 PM.
Race Director
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From: A 12/8 man in a 4/4 world
