NO heat!!!!
Thread Starter
Le Mans Master
Joined: Jun 2005
Posts: 9,948
Likes: 0
From: Hudson Valley Region, NY The "sonoma/napa" of the Northeast~~~~~ Are we there yet?
St. Jude Donor '08
NO heat!!!!
Ok.. so I have no heat... Its a 93.. the two hoses in the motor are hot, and the fan blows.. but no heat! No matter what temp I set it on, it just blows cold. I dont know where to begin and I dont want to get ripped at the local mechanic... any ideas on where to start or what might be causing this.
If it helps.. the car isnt a daily driver and the heat hasnt worked since last fall... I just dont drive it in the winter so it wasnt a priority. It stopped working last fall when I went to put the defroster on one night.. I smelled a little antifreeze but no leak and then it just stopped being warm. I have tried the heat on a few occassions since and there is no more smell but it still just blows cold...
I cant take the cold no more! Help!!!
If it helps.. the car isnt a daily driver and the heat hasnt worked since last fall... I just dont drive it in the winter so it wasnt a priority. It stopped working last fall when I went to put the defroster on one night.. I smelled a little antifreeze but no leak and then it just stopped being warm. I have tried the heat on a few occassions since and there is no more smell but it still just blows cold...
I cant take the cold no more! Help!!!
Safety Car
Joined: Oct 2000
Posts: 4,233
Likes: 355
From: Albuquerque, NM
Check for a vacuum leak in the system that controls the doors (the doors inside the heater box assembly that direct airflow through the system). The factory service manual would probably help a lot, but I remember hearing about one vacuum hose, fitting, or connection that often breaks. It's next to the passenger side valve cover under the black cover.
Last edited by BlackbirdZ07; Mar 5, 2007 at 06:30 PM.
Pro
Joined: Jan 2004
Posts: 653
Likes: 0
From: Northern New Jersey
St. Jude Donor '03-'05-'06-'07-'08
SRG
I have the exact problem with my 93, but I dont use it during the winter so I never bothered to try & fix it.
This thread has some good info & hopefully it will help you.
http://forums.corvetteforum.com/show...limate+control
I have the exact problem with my 93, but I dont use it during the winter so I never bothered to try & fix it.
This thread has some good info & hopefully it will help you.
http://forums.corvetteforum.com/show...limate+control
Instructor
Joined: Aug 2006
Posts: 247
Likes: 0
If you have the electronic climate control, I'll bet it's the "Programmer" unit. This is a little black box that, among other things, signals a motor to swing a little door back and forth in the heater box area to give you warm air or cold air. I think the motor defaults to "cold" if the Programmer fails. To check for it, try all the functions OTHER than the temperature control for the heat. If all the air in the system blows where it should in the particular function (e.g., to the floor, out the vents etc.), the air conditioning works, etc., its probably the "Programmer" that's the problem. I got a new one for my '89 from GMPartsDirect.com for about $130. I installed it myself by taking off the lower dash panel (the one with the light) on the driver's side, and simply unplugging the old one and plugging in the new one. Everything worked perfectly after that.
Cheers,
Chris Kennedy
Cheers,
Chris Kennedy
Racer
Joined: Jun 2006
Posts: 408
Likes: 0
From: Elkton MD
No Heat
If you have the automatic A/C, turn the temp all the way up (90?). If it gets hot, the ambient air temp sensor is shot. Way less than $100 and an easy do-it-yourselfer.
If you have manual A/C or if the automatic remains cold at max temp, try flushing the heater core. Don't use too much pressure as the core only sees ~15psi in normal operation.
Good luck.
If you have manual A/C or if the automatic remains cold at max temp, try flushing the heater core. Don't use too much pressure as the core only sees ~15psi in normal operation.
Good luck.
Thread Starter
Le Mans Master
Joined: Jun 2005
Posts: 9,948
Likes: 0
From: Hudson Valley Region, NY The "sonoma/napa" of the Northeast~~~~~ Are we there yet?
St. Jude Donor '08
thank you for all the advice, Im going to tinker with it some tomorrow.
Trying to get it fixed before race season!
Ill report back on my findings...
Trying to get it fixed before race season!
Ill report back on my findings...
Elite Torch Red Member
Joined: Sep 1999
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
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St. Jude Donor '03-'04-'05-'06-'07
I guess I'll have to keep you warm on Saturday.
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Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
I had the same problem on my 92 and found it to be an air lock in the cooling system. I raised the front of the car, drained the rad and removed the t-stat. I drilled a small hole in the t-stat and reinstalled it. Filled the rad with coolant, cranked it and burped the system and bled the little valve on top of the t-stat housing. Now the car gets nice and warm on the coldest days. Worked for me, I hope your problem is no more serious than mine.
Bernie
Bernie
Thread Starter
Le Mans Master
Joined: Jun 2005
Posts: 9,948
Likes: 0
From: Hudson Valley Region, NY The "sonoma/napa" of the Northeast~~~~~ Are we there yet?
St. Jude Donor '08
Im sooo not speaking to you!!!
# count them frank... 3 years.. and Im still cold!!! WTF!
Im taking to my buddies garage tonight and we are going to see what we can figure out. It needs to get fixed for two major reasons
1. I dont think its wise to keep pushing the car at the track and not really know whats going on
2. I will literally be a frozen kimsicle by the time I get to the track w/o heat and there ISNT anyone there to warm me up!
So.. if you have any words of wisdom on how to fix this call me tonight.. ill be elbow deep in the hood
# count them frank... 3 years.. and Im still cold!!! WTF!Im taking to my buddies garage tonight and we are going to see what we can figure out. It needs to get fixed for two major reasons
1. I dont think its wise to keep pushing the car at the track and not really know whats going on
2. I will literally be a frozen kimsicle by the time I get to the track w/o heat and there ISNT anyone there to warm me up!
So.. if you have any words of wisdom on how to fix this call me tonight.. ill be elbow deep in the hood
Thread Starter
Le Mans Master
Joined: Jun 2005
Posts: 9,948
Likes: 0
From: Hudson Valley Region, NY The "sonoma/napa" of the Northeast~~~~~ Are we there yet?
St. Jude Donor '08
is it possible to get advice on here without someone... or someones... making innuendos
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
What my car's "no heat" problem was
Mine is a '95..no heat. Flushed the heater core....didn't change.
Went through the diagnoistcs of the auto temp controls....no error codes.
Finally took the passenger side lower trim panel off to see if the air mix door was moving, it was not. Took of the motor module and found a dirty solder joint on the little dc motor. Re-flowed the solder and after about five tries figured out the correct position of the gears in relation to the air mix door shaft. And I have heat now. Drop the motor off with two screws and see if the door will rotate with your fingers. It could be stuck.
Hint here...if you do take the motor module off and apart..look for two small alignment marks for the full hot and full cold positions. Turn the door with your fingers to either the full hot or full cold. Set your temp controls to the same (full hot or full cold)....and align the drive gear of the motor module with these marks and re-install.
Good luck,
LannyL81
Went through the diagnoistcs of the auto temp controls....no error codes.
Finally took the passenger side lower trim panel off to see if the air mix door was moving, it was not. Took of the motor module and found a dirty solder joint on the little dc motor. Re-flowed the solder and after about five tries figured out the correct position of the gears in relation to the air mix door shaft. And I have heat now. Drop the motor off with two screws and see if the door will rotate with your fingers. It could be stuck.
Hint here...if you do take the motor module off and apart..look for two small alignment marks for the full hot and full cold positions. Turn the door with your fingers to either the full hot or full cold. Set your temp controls to the same (full hot or full cold)....and align the drive gear of the motor module with these marks and re-install.
Good luck,
LannyL81
Melting Slicks
Joined: Mar 2006
Posts: 2,455
Likes: 6
From: MichAgain
Heater core?
If both the hoses to the heater core are hot, I would rule out a plugged HC as the culprit. If only the input were hot but the return were cold then yes, plugged core.
I'd be looking into the air diverter mech...
Good luck
I'd be looking into the air diverter mech...
Good luck
Thread Starter
Le Mans Master
Joined: Jun 2005
Posts: 9,948
Likes: 0
From: Hudson Valley Region, NY The "sonoma/napa" of the Northeast~~~~~ Are we there yet?
St. Jude Donor '08
ok so all the electronics on the dash work, the hoses are hot.. but no heat still.. after some investigation it looks as though the previous owener had some issues too.. im missing some screws and the box containing that flap is cracked. 
still working on it.. any further advice? How bad is it to run the car without the heat working??? that is assuming I cant fix it....
still working on it.. any further advice? How bad is it to run the car without the heat working??? that is assuming I cant fix it....
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
I ran my '85 for 2 years without a working heater. Till my GF complained enough to get me to fix it. On my '85 (manual controls) the heater door wasn't moving, the fix wasn't too bad, the hardest part was getting to it. Your 93 is probably too different for me to offer any advice other then that, however.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Plugged cores have coolant flowing over the top but not through it (can you imagine what would happen if the flow stopped?). Both hoses being hot doesn't mean much. I believe there is a checkvalve on this Year at the source - make sure it's not plugged.
Before tearing apart the interior, you can view the temp door by removing the Blower Module on the Evaporator Case - part jutting out of the passenger side firewall. Look inside while someone operates the controls between 60 and 90. If it doesn't move, suspect the motor which on this Year is directly connected to the door's linkage. If you have a bi-directional scanner, hook it up to the CCM link and see if you can make it work. That will rule out the Dash Controls and serial data lines to the Programmer. Otherwise, I would check to make sure there's voltage and ground at the motor. There's usually more than 2 wires, but verifying voltage isn't going to hurt anything. If you find voltage it's the motor - If not, usually the Programmer.
Before tearing apart the interior, you can view the temp door by removing the Blower Module on the Evaporator Case - part jutting out of the passenger side firewall. Look inside while someone operates the controls between 60 and 90. If it doesn't move, suspect the motor which on this Year is directly connected to the door's linkage. If you have a bi-directional scanner, hook it up to the CCM link and see if you can make it work. That will rule out the Dash Controls and serial data lines to the Programmer. Otherwise, I would check to make sure there's voltage and ground at the motor. There's usually more than 2 wires, but verifying voltage isn't going to hurt anything. If you find voltage it's the motor - If not, usually the Programmer.
Thread Starter
Le Mans Master
Joined: Jun 2005
Posts: 9,948
Likes: 0
From: Hudson Valley Region, NY The "sonoma/napa" of the Northeast~~~~~ Are we there yet?
St. Jude Donor '08
ok so its not the flap on that door... still freezing.. I think Im just going to bring it to the dealer..