New to Corvettes
01-26-2007, 11:59 AM
#1
Intermediate
Thread Starter
New to Corvettes
Greetings! I'm new to Corvettes and this forum. I recently purchased a 1993 LT1 convertible. I've been reading some of the past posts and this seems to be a very active and supportive forum. The recent cold weather has uncovered a problem with my car that perhaps someone here can provide guidance on. The heat in my car is weak at best, the fan works and the air distrubution routines seem to working as well. The car shows teperatures right around mid-range on the gauge when completely warmed up, but no real heat. What comes out of the vents is lukewarm at best. I've had the thermostat replaced (180 degree), cooling system flushed and coolant replaced, with no improvement. Does anyone have any ideas as to what the problem might be?
TIA
James
TIA
James
01-26-2007, 12:17 PM
#2
Melting Slicks
Member Since: Nov 2002
Location: 1993 Quasar Blue 'vert Scottsdale AZ
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Welcome. I have a '93 convertible also and had the same problem with mine. I had an extended warranty, took it to the shop and replaced what they called a "heater control valve". Whatever that is, it did the trick. Very hot air now.
01-26-2007, 12:54 PM
#3
Le Mans Master
James,
Fill out your public view(user cp) so we know who you are and what you drive.
The cold does uncover many problems and hides others.
Good luck and welcome aboard.
Fill out your public view(user cp) so we know who you are and what you drive.
The cold does uncover many problems and hides others.
Good luck and welcome aboard.
01-26-2007, 02:48 PM
#5
Team Owner
Member Since: Dec 2000
Location: SE NY
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Cruise-In II Veteran
Welcome to the Forum and congrats on your new '93 Vette...
Do you have electronic or manual HVAC control?
After the engine is warmed up (carefully) grab the heater hose into the heater and then the one out of the heater; they should both be rather hot if flow is good. In that case the problem is in the HVAC control system; else it could be a clogged heater core.
On my '88 with RPO C68 there is a Air Mix Valve Actuator that controls the Temperature Valve; the latter is simply a door that moves within the air delivery plenum to control how much air goes through the heater core after it flow through the A/C evaporator core.
If this "door" is not allowing enough air flow through the heater core you will get cold/cool air delivered.
Do you have electronic or manual HVAC control?
After the engine is warmed up (carefully) grab the heater hose into the heater and then the one out of the heater; they should both be rather hot if flow is good. In that case the problem is in the HVAC control system; else it could be a clogged heater core.
On my '88 with RPO C68 there is a Air Mix Valve Actuator that controls the Temperature Valve; the latter is simply a door that moves within the air delivery plenum to control how much air goes through the heater core after it flow through the A/C evaporator core.
If this "door" is not allowing enough air flow through the heater core you will get cold/cool air delivered.
Last edited by 65Z01; 01-26-2007 at 02:55 PM.
01-26-2007, 03:32 PM
#6
Intermediate
Thread Starter
New to Corvettes with a heater problem
Welcome to the Forum and congrats on your new '93 Vette...
Do you have electronic or manual HVAC control?
After the engine is warmed up (carefully) grab the heater hose into the heater and then the one out of the heater; they should both be rather hot if flow is good. In that case the problem is in the HVAC control system; else it could be a clogged heater core.
On my '88 with RPO C68 there is a Air Mix Valve Actuator that controls the Temperature Valve; the latter is simply a door that moves within the air delivery plenum to control how much air goes through the heater core after it flow through the A/C evaporator core.
If this "door" is not allowing enough air flow through the heater core you will get cold/cool air delivered.
Do you have electronic or manual HVAC control?
After the engine is warmed up (carefully) grab the heater hose into the heater and then the one out of the heater; they should both be rather hot if flow is good. In that case the problem is in the HVAC control system; else it could be a clogged heater core.
On my '88 with RPO C68 there is a Air Mix Valve Actuator that controls the Temperature Valve; the latter is simply a door that moves within the air delivery plenum to control how much air goes through the heater core after it flow through the A/C evaporator core.
If this "door" is not allowing enough air flow through the heater core you will get cold/cool air delivered.
Thanks
01-26-2007, 04:28 PM
#7
Safety Car
Welcome to the Forum James.
This is an interesting thread, as my car is doing the same thing.
James, please let us know how you resolve this.
This is an interesting thread, as my car is doing the same thing.
James, please let us know how you resolve this.
01-26-2007, 04:54 PM
#8
Le Mans Master
Jim, first off, welcome to the forum. Raise the hood and look for an electrical connection on top of the heater box. This is connected to a resistor. Now the resistor has 2 or 3 screws mounting it to the heater box. Take those loose and take a flashlight and look down in the box. You should see a damper down in there and it opens and closes by the motor that is referenced above. Now take a long screwdriver and see if it moves back and forth easly. If it does, the linkage going to the motor is broke. This is a common problem on these cars. 
Assuming it is broke, you can swing it one way to open it and the other way to close it. I have been doing this for 2 years now, setting it to the season we are in, ie. heat or cool. The part is very cheap, but you have to remove the dash to get to it. I was told that they redesigned it in 94 or 95 and put the motor on the bottom of the heater box so it could be accessed from under the dash. But for us, its on top of the box and requires removal of the dash to repair it. Also, I was told that you can use the heater box from the newer ones and they will bolt in. Then, in the future, if it breaks again, you can access it from under the dash, oh and you have to reverse the wires on the motor. Good Luck, and bring that car to manassas this spring for a test and tune at our local track!!
Assuming it is broke, you can swing it one way to open it and the other way to close it. I have been doing this for 2 years now, setting it to the season we are in, ie. heat or cool. The part is very cheap, but you have to remove the dash to get to it. I was told that they redesigned it in 94 or 95 and put the motor on the bottom of the heater box so it could be accessed from under the dash. But for us, its on top of the box and requires removal of the dash to repair it. Also, I was told that you can use the heater box from the newer ones and they will bolt in. Then, in the future, if it breaks again, you can access it from under the dash, oh and you have to reverse the wires on the motor. Good Luck, and bring that car to manassas this spring for a test and tune at our local track!!
01-26-2007, 05:53 PM
#9
Intermediate
Thread Starter
Jim, first off, welcome to the forum. Raise the hood and look for an electrical connection on top of the heater box. This is connected to a resistor. Now the resistor has 2 or 3 screws mounting it to the heater box. Take those loose and take a flashlight and look down in the box. You should see a damper down in there and it opens and closes by the motor that is referenced above. Now take a long screwdriver and see if it moves back and forth easly. If it does, the linkage going to the motor is broke. This is a common problem on these cars. Assuming it is broke, you can swing it one way to open it and the other way to close it. I have been doing this for 2 years now, setting it to the season we are in, ie. heat or cool. :
Assuming it is broke, you can swing it one way to open it and the other way to close it. I have been doing this for 2 years now, setting it to the season we are in, ie. heat or cool. :
01-26-2007, 06:21 PM
#10
Burning Brakes
C4 ragtops are one of the most beautiful cars ever made (with the top is down). I nearly bought a dark green '93 with saddle interior in addition to my '88 just to look at it. I always was a sucker for a pretty face.
And pretty faces tend to be high maintenance. Welcome aboard!
And pretty faces tend to be high maintenance. Welcome aboard!
Last edited by GeosFun; 01-26-2007 at 06:24 PM.
01-26-2007, 06:32 PM
#11
Burning Brakes
Member Since: Mar 2006
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C4 ragtops are one of the most beautiful cars ever made (with the top is down). I nearly bought a dark green '93 with saddle interior in addition to my '88 just to look at it. I always was a sucker for a pretty face. And pretty faces tend to be high maintenance. Welcome aboard!
And pretty faces tend to be high maintenance. Welcome aboard!
High maintenance, indeed, but (in my experience, at least) worth it.Good luck, and welcome to one of the more interesting places in Cyberspace!