HVAC: driver sde HOT, pass COLD
Thread Starter
Melting Slicks
Joined: Apr 2003
Posts: 2,285
Likes: 16
From: Nashville TN
HVAC: driver sde HOT, pass COLD
I know this has been covered before, but I did a search and could not find the answer. When I turn the ac/heat on I get heat from the driver side vents and cold air from the pass side vents. I just replaced the engine so I might have a line or wire loose somewhere. Can some tell me where to start looking?
Thanks
Thanks
Race Director
Joined: Mar 2001
Posts: 10,030
Likes: 10
From: Prescott AZ
St. Jude Donor '04
I know this has been covered before, but I did a search and could not find the answer. When I turn the ac/heat on I get heat from the driver side vents and cold air from the pass side vents. I just replaced the engine so I might have a line or wire loose somewhere. Can some tell me where to start looking?
Thanks
Thanks
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Check your codes and possibly try reindexing the actuators.
http://forums.corvetteforum.com/c5-t...actuators.html
http://forums.corvetteforum.com/c5-t...actuators.html
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Check your DTC abd see if you have any HVAC DTCs If you do try this:
- Turn the key to ON, dont start the engine.
- Turn the HVAC unit OFF.
- Reset the DTCs and when you do listen carefully inside the dash for the HVAC actuators to index. When they stop,
- Start the engine and bring it up to temperature so you can test the heat/cold function of the HVAC unit.
- Turn the HVAC unit ON and test.
- Check the DTC for HVAC codes. If they come on again, it will tell you which actuator is failing.
If it doesnt work try to do the procedure a couple more times. I had to do it three times on my 02 Z before it fixed the issue. Its been good ever since.
If you find that you ever cant change the VENT positions, those are controlled by VACUUM and the vacuum comes fron the small line on the back of the intake manifold.
Let us know how you make out.
BC
- Turn the key to ON, dont start the engine.
- Turn the HVAC unit OFF.
- Reset the DTCs and when you do listen carefully inside the dash for the HVAC actuators to index. When they stop,
- Start the engine and bring it up to temperature so you can test the heat/cold function of the HVAC unit.
- Turn the HVAC unit ON and test.
- Check the DTC for HVAC codes. If they come on again, it will tell you which actuator is failing.
If it doesnt work try to do the procedure a couple more times. I had to do it three times on my 02 Z before it fixed the issue. Its been good ever since.
If you find that you ever cant change the VENT positions, those are controlled by VACUUM and the vacuum comes fron the small line on the back of the intake manifold.
Let us know how you make out.
BC
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
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Thread Starter
Melting Slicks
Joined: Apr 2003
Posts: 2,285
Likes: 16
From: Nashville TN
I did the test per Bill.
I can hear the actuators moving. I am also able to switch between modes, so my vac lines must be good. However after running the test 3 times I get warm air from the center and driver door vent and cold air from the pass vents. Also the airflow from the pass vents is twice as much as the center vent. I am getting the following codes:
B0432
B0502
B0507
B2482
B0446
So what's the next step?
Thanks
I can hear the actuators moving. I am also able to switch between modes, so my vac lines must be good. However after running the test 3 times I get warm air from the center and driver door vent and cold air from the pass vents. Also the airflow from the pass vents is twice as much as the center vent. I am getting the following codes:
B0432
B0502
B0507
B2482
B0446
So what's the next step?
Thanks
Melting Slicks
Joined: Oct 2007
Posts: 2,798
Likes: 8
From: It's true money can't buy happiness, but it is more comfortable crying in a Corvette than on a bicyc
St. Jude Donor '13
Yep. I doubted it. I reset the actuators. Pulled the codes. And still ignored the add freon advice. Gave up. Decided what would I lose, 10 bucks? Broke down added 1 can and low and behold my A/C will freeze you out. OK, so why? The explanation I received was the climate control system for the passenger side uses the lower half of the evaporator while the drivers side air goes through the upper half. When the freon is low the passenger side gets colder. Made sense to me and more so since adding freon worked for me. So that's my standard advice to anyone with cold passenger side and warmer drivers side air. And like I decided 10 bucks isn't much to lose on a fix. Try it and either thank me or hate me. Or do a search and read all of those who have went there before you.
Thread Starter
Melting Slicks
Joined: Apr 2003
Posts: 2,285
Likes: 16
From: Nashville TN
Yep. I doubted it. I reset the actuators. Pulled the codes. And still ignored the add freon advice. Gave up. Decided what would I lose, 10 bucks? Broke down added 1 can and low and behold my A/C will freeze you out. OK, so why? The explanation I received was the climate control system for the passenger side uses the lower half of the evaporator while the drivers side air goes through the upper half. When the freon is low the passenger side gets colder. Made sense to me and more so since adding freon worked for me. So that's my standard advice to anyone with cold passenger side and warmer drivers side air. And like I decided 10 bucks isn't much to lose on a fix. Try it and either thank me or hate me. Or do a search and read all of those who have went there before you.
I disconnected the battery last night and the problem is still there along with the 0446 code. So I guess I need to re-index the actuators. Gotta pull the dash. Is it right to assume that the actuator is working properly just out of range since I am getting a code?
It is just weird that a prolonged period with the battery disconnected would cause this problem.
Also can someone verify that the airflow should be equal across all the vents. My center is noticeably weaker.
THanks
Thread Starter
Melting Slicks
Joined: Apr 2003
Posts: 2,285
Likes: 16
From: Nashville TN
OK so that might work if you are running the AC and the driver side is not getting cold enough. My problem is when I turn the heat on. The pass side is cold while the driver side is warm.
I disconnected the battery last night and the problem is still there along with the 0446 code. So I guess I need to re-index the actuators. Gotta pull the dash. Is it right to assume that the actuator is working properly just out of range since I am getting a code?
It is just weird that a prolonged period with the battery disconnected would cause this problem.
Also can someone verify that the airflow should be equal across all the vents. My center is noticeably weaker.
THanks
I disconnected the battery last night and the problem is still there along with the 0446 code. So I guess I need to re-index the actuators. Gotta pull the dash. Is it right to assume that the actuator is working properly just out of range since I am getting a code?
It is just weird that a prolonged period with the battery disconnected would cause this problem.
Also can someone verify that the airflow should be equal across all the vents. My center is noticeably weaker.
THanks
Burning Brakes
Joined: Aug 2004
Posts: 770
Likes: 0
Resequence the actuators first, followed by recording and clearing all the codes. Then run the car and see which codes have returned.
Next figure out what the codes refer to. B0446 is the right actuator out of range. I had trouble (B0441) with my left actuator. Mine code would keep coming back after the resequence.
I was able to fix it by turning the shaft (slightly) by putting a screwdriver into the the slot on the end of the shaft and then did a resequence. You may be able to try this for the right side actuator as well.
You have a lot of codes. Do you know what they mean? Here is a good ref for codes...http://www.aceesolutions.com/vette/2002dtc.html
I wonder if you have a ground lose or low battery voltage? That is a lot of relay circut codes for so many different things.
Good luck,
Doug
Next figure out what the codes refer to. B0446 is the right actuator out of range. I had trouble (B0441) with my left actuator. Mine code would keep coming back after the resequence.
I was able to fix it by turning the shaft (slightly) by putting a screwdriver into the the slot on the end of the shaft and then did a resequence. You may be able to try this for the right side actuator as well.
You have a lot of codes. Do you know what they mean? Here is a good ref for codes...http://www.aceesolutions.com/vette/2002dtc.html
I wonder if you have a ground lose or low battery voltage? That is a lot of relay circut codes for so many different things.
Good luck,
Doug
Melting Slicks
Joined: Oct 2007
Posts: 2,798
Likes: 8
From: It's true money can't buy happiness, but it is more comfortable crying in a Corvette than on a bicyc
St. Jude Donor '13
I just reread your original post. I have to apologize I thought you had an AC problem. So I assumed Freon would fix it. Now I see it's a heater/ac issue.
One question though, Did everything work normal before the engine job? As Bill C posted there is a vacuum line on the back of the manifold that can get overlooked or splits that can give you issues. With the low airflow out of the center and heat out of the drivers and AC out of the passenger side it sounds more like a vacuum/actuator issue.
One question though, Did everything work normal before the engine job? As Bill C posted there is a vacuum line on the back of the manifold that can get overlooked or splits that can give you issues. With the low airflow out of the center and heat out of the drivers and AC out of the passenger side it sounds more like a vacuum/actuator issue.
Thread Starter
Melting Slicks
Joined: Apr 2003
Posts: 2,285
Likes: 16
From: Nashville TN
I ahve done teh resequence and that did not fix it.
The other codes are nothing to worry about. I know why they are there.
It was my understanding that if teh AC will change modes(ie, floor, defrost, etc) then the system is getting good vacuum. It did work before the tear down, but the car sat for almost a year with the battery disconnected.
The other codes are nothing to worry about. I know why they are there.
It was my understanding that if teh AC will change modes(ie, floor, defrost, etc) then the system is getting good vacuum. It did work before the tear down, but the car sat for almost a year with the battery disconnected.
2nd Gear
Joined: Feb 2009
Posts: 2
Likes: 0
HVAC: driver sde cold, pass Hot
My batt was dead for about 6months, when I replaced the batt. this problem started. If I access the codes on the dash the HVAC has 3 codes, when I reset the code the pass will blow cold for about 3 sec. then go back to blowing hot. The driver side stays cold.
Burning Brakes
Joined: Aug 2004
Posts: 770
Likes: 0
Chris,
Why is the right actuator out of range. When you clear this code with the key on and the engine off, you should hear the actuator go thru a sequence of moves 6 times to calibrate the actuator range. Listen closley while this is happening. If it won't make it thru all of this excercise, it will pop the code and the actuator will not work properly.
As I said in my above post - after it fails this test - put a screwdriver into the slot on the end of the shaft of the right actuator and turn it slightly. Also use a zoom spout oiler to spritz the end of the shaft to lube it. Then clear the code again and listen as it goes thru the indexing procedeure. This will work if you will just try it.
Ha, don't make me come out there.
Why is the right actuator out of range. When you clear this code with the key on and the engine off, you should hear the actuator go thru a sequence of moves 6 times to calibrate the actuator range. Listen closley while this is happening. If it won't make it thru all of this excercise, it will pop the code and the actuator will not work properly.
As I said in my above post - after it fails this test - put a screwdriver into the slot on the end of the shaft of the right actuator and turn it slightly. Also use a zoom spout oiler to spritz the end of the shaft to lube it. Then clear the code again and listen as it goes thru the indexing procedeure. This will work if you will just try it.
Ha, don't make me come out there.
Thread Starter
Melting Slicks
Joined: Apr 2003
Posts: 2,285
Likes: 16
From: Nashville TN
I have tried resequencing and the code comes back. Yes you can hear it going through its cycle. I will pull the dash and find the actuator. I will try the screwdriver trick before, tearing the actuator apart and re-indexing the gear. If I can get off work, I'll tackle it this weekend.
Burning Brakes
Joined: Aug 2004
Posts: 770
Likes: 0
Right on Chris. FYI - the left side actuator is accessible from under the d/s dash. You may want to look in your service manual to see if the right side actuator is as well.
Or just follow the sound as you clear the code and see if you can reach it with a small common screw driver. Good luck.
Or just follow the sound as you clear the code and see if you can reach it with a small common screw driver. Good luck.