Installed New Batt-Now AC only blows hot air SOS
10-03-2012, 07:21 PM
#1
Burning Brakes
Thread Starter
Installed New Batt-Now AC only blows hot air SOS
I've had my C5 do the typical hot air driver side/cold air passanger side- it usually means she wants a can of 134 and then we're good again. The AC was working great, had to put a new battery in, and now the AC only blows hot air out both sides. Gets a little hotter when you turn up the temp, but always hot. Compressor is kicking on when you turn on the AC, and I'm showing a good charge on the AC when I hook up my gauges. Tried clearing codes, pulling fuses and relay, no joy. Any suggestions?? Thanks in advance to all- 97C5 
10-04-2012, 11:15 AM
#3
Burning Brakes
Thread Starter
Had 5 hvac codes- cleared them- could hear the doors in the dash moving, then all 5 codes came back. Now getting semi cool air driver side-hot air passenger side when ac set to 60.
10-04-2012, 11:34 AM
#4
Burning Brakes
Vacuum lines.... they are down under/behind the battery tray. Did your last battery leak? The lines are plastic and get brittle after all these years. I've chased leaks in mine twice now. Different issues each time, but same root cause.
10-04-2012, 03:59 PM
#6
Racer
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Typical problem with the encoder motors (EMs control all the blend door positions for the HVAC)on all GM vehicles when you disconnect the battery. You should have used one of the cigarette lighter battery taps to keep voltage to the system while changing the battery.There is a recalibration procedure that MAY restore the function,but you also may need to replace an encoder motor or two.
10-04-2012, 08:51 PM
#7
Burning Brakes
Thread Starter
Typical problem with the encoder motors (EMs control all the blend door positions for the HVAC)on all GM vehicles when you disconnect the battery. You should have used one of the cigarette lighter battery taps to keep voltage to the system while changing the battery.There is a recalibration procedure that MAY restore the function,but you also may need to replace an encoder motor or two.
10-04-2012, 09:15 PM
#9
Team Owner
Typical problem with the encoder motors (EMs control all the blend door positions for the HVAC)on all GM vehicles when you disconnect the battery. You should have used one of the cigarette lighter battery taps to keep voltage to the system while changing the battery.There is a recalibration procedure that MAY restore the function,but you also may need to replace an encoder motor or two.
If the main gear inside the actuator breaks loose from the shaft, it won't position things correctly and the feedback that is offered (analog pot signal), won't really relate to any absolute position. IE, it won't set proper limits. From that point on, the system cannot tell the actuator where to put the doors, and you get all sorts of temp issues. (and codes). The system knows when an error has occurred with positioning, and it sets codes accordingly.
Since you cleared the codes, this is very odd. You're getting conflicting information. The feedback circuit can't be open and shorted to ground at the same time. Time to start checking wiring to the actuators and see if you don't have some wires with insulation chaffed off. Something is grounded sometimes and open at others. Or the system thinks so anyway. Since more codes are driver side related, I'd start there. Look up under the dash near the steering column, and see if you can't find some wiring issues there. You may end up delving into your service manual to do some more serious wiring diagnostics if something isn't obvious.
This may help with your P1571
http://forums.corvetteforum.com/c5-t...ighlight=P1571
Last edited by K-Spaz; 10-04-2012 at 09:31 PM.
10-05-2012, 12:06 AM
#10
Instructor
I just reset the codes a dozen or so times until it finally starts blowing cold air. reset code, start car, test A/C. repeat as many times as it takes. works for me.
10-05-2012, 09:00 AM
#11
Team Owner
Sounds like you also have an actuator with a broken gear, and while it might be tight enough to work once in a while, it won't be long before you're in there replacing yours too.
10-06-2012, 05:02 PM
#12
This procedure works for me too. Give it a try....again and again until it works or your fingers fall off.
10-09-2012, 11:07 PM
#14
Team Owner
Pretty much, yes. Clear the HVAC codes (if present) and the system will begin a recalibrate on the actuators within seconds. You don't even have to exit the codes list, or at least on my car you don't have to.
10-10-2012, 11:37 AM
#15
Burning Brakes
Thread Starter
If I can't clear them. What do I need to do to get her straightened out? Replace the actuators w new?
10-10-2012, 04:08 PM
#16
Team Owner
I don't recall if you said you have dual climate control or not? If so, yes it's the expensive one. If you have manual A/c, they are $4x.00
Yes, it's just robbery. They are the same damn part with a big price diff.
10-10-2012, 06:17 PM
#17
Burning Brakes
Thread Starter
Pretty much, yes. They're occasionally on sale at Advance Auto or Auto Zone for $90 each. Typically $115 or so.
I don't recall if you said you have dual climate control or not? If so, yes it's the expensive one. If you have manual A/c, they are $4x.00
Yes, it's just robbery. They are the same damn part with a big price diff.
I don't recall if you said you have dual climate control or not? If so, yes it's the expensive one. If you have manual A/c, they are $4x.00
Yes, it's just robbery. They are the same damn part with a big price diff.
10-10-2012, 07:42 PM
#18
Team Owner
I think there's writeups here on the forum with photos. I know Bill has some good info. There are two electric actuators, the rest are vacuum. They are on either side of the air box. I did my passengers side while I had other things out so I can't say how easy it would be with what you have removed. As I recall from the position though, you should be able to get it from underneath. I don't have my service manual here or I'd look that up.
The drivers side is easy. You remove the knee panels on that side and go up from underneath. Yea, it's awkward, but it's not that bad. There's 3 screws and an electrical connection. Take out the old, line up the shaft, stick in the new. Pretty simple.
The codes should tell you which is failed. But in your case, with the conflicting codes 0361/0363, I'd ask someone here who's more knowledgeable than I. I don't understand why you're getting both of those, I can understand getting one or the other. Somethings flaky on the drivers side. Maybe someone else here has seen those two codes together. From what it says, both are broken.
Having the center bezel off does kinda help a little with the driver side. Just with being able to see. I did all the work from underneath tho. Again, I can't recall the passenger side cause I had the entire car torn apart. Nothing in the way when you're in to the firewall!
Here's a post with some good basic info.
http://forums.corvetteforum.com/c5-g...bees-only.html
ps. the screws are a 7mm head coarse thread self tapping (for plastic)
[edit again]
Here's a photo of mine. (you can see why my right side was easier!)
Take a look at the two large openings front and center. The actuators are on either side of the "upper" opening as viewed in this pic. The one on the left is quite easy to see, the one on the right is sorta obscured behind the vacuum dashpot and the colored vacuum hoses. They lay flat on the sides of the air box. If you look close you can see the door shaft and output drive shaft of the door and actuator on the right. It's a cream colored plastic shaft and a white metal drive. The rest of the black thing is the passengers side actuator.
Consider that whole thing goes up and the foam seal shown is against your upper dash pad. That will give you some idea of how high up those are. Yea, they could be in an easier position.
The drivers side is easy. You remove the knee panels on that side and go up from underneath. Yea, it's awkward, but it's not that bad. There's 3 screws and an electrical connection. Take out the old, line up the shaft, stick in the new. Pretty simple.
The codes should tell you which is failed. But in your case, with the conflicting codes 0361/0363, I'd ask someone here who's more knowledgeable than I. I don't understand why you're getting both of those, I can understand getting one or the other. Somethings flaky on the drivers side. Maybe someone else here has seen those two codes together. From what it says, both are broken.
Having the center bezel off does kinda help a little with the driver side. Just with being able to see. I did all the work from underneath tho. Again, I can't recall the passenger side cause I had the entire car torn apart. Nothing in the way when you're in to the firewall!
Here's a post with some good basic info.
http://forums.corvetteforum.com/c5-g...bees-only.html
ps. the screws are a 7mm head coarse thread self tapping (for plastic)
[edit again]
Here's a photo of mine. (you can see why my right side was easier!)
Take a look at the two large openings front and center. The actuators are on either side of the "upper" opening as viewed in this pic. The one on the left is quite easy to see, the one on the right is sorta obscured behind the vacuum dashpot and the colored vacuum hoses. They lay flat on the sides of the air box. If you look close you can see the door shaft and output drive shaft of the door and actuator on the right. It's a cream colored plastic shaft and a white metal drive. The rest of the black thing is the passengers side actuator.
Consider that whole thing goes up and the foam seal shown is against your upper dash pad. That will give you some idea of how high up those are. Yea, they could be in an easier position.
Last edited by K-Spaz; 10-10-2012 at 08:04 PM. Reason: add a photo
10-11-2012, 12:19 AM
#19
Instructor
Well it works and blows cold air. Ive had to do this several times after disconnecting the battery, and every time this does the trick. Took me only 3 tries tonight.
10-11-2012, 09:05 AM
#20
Team Owner
