you might try reindexing the actuators.
Turn the key to "on" position,but don't start the car
Make sure the A/C is off.

Hit reset to clear any warnings on DIC (Door ajar,etc.)

Hold the "Options" button down while pressing the "Fuel" button four times within 10 seconds.
This will bring up the "Diagnostics" text on the DIC
Hit "options" again,and the DIC will display "Manual Diagnostics"
Keep pressing "reset" till you come to "99HVAC"
Press and hold the reset button(even if there's no codes) till it beeps .
You'll hear the actuator motors under the dash running for 20 seconds or so(they're not very loud,so listen closely)
Give it another 10 seconds or so after they stop,then turn the key off.

Now start the car and try the A/C -if reindexing is going to help,the A/C should work if its just a calibration issue.
If not,it's time to dig deeper.
Next is to check the gears in the actuator.

Steve

 

thanks! I appreciate the help. I'll see what this fuse thing does then give that a try as well. at least I don't have to take things apart to do that. its not so fun to work on a car in a 20 degree garage. better that than 90 imo, but still not fun.

 

I know this is annoying, but are you sure you are not throwing any codes on the DIC?
Have you checked them while this is happening? With all safety cautions, you can do this while driving, while this is happening. Its a little strange that nothing is showing up.
If I were you, go to the HVAC while this is happening and check for codes, if nothing is there, hit the reset and see if there is a reaction. I had to do this a number of times ( but during the AC weather, as I was getting warm air when I wanted cold). Even though no codes showed up, it did change when I did this. Not saying this will work, but, it won't hurt either.

 

I think he was throwing codes for the passenger side. I think he's going to have to replace the actuator on the passenger side. Its the same part# for both sides. Hint, I got mine from RockAuto this time rather, Dorman, to save some money as opposed to the AC Delco part. It worked fine.

 

I guess I could give that a try. I would think that if a code were thrown I'd at least have an H code. right now I'm not getting any. I haven't checked them today but I did check after the last incident which resulted in this thread being created in the first place, HVAC section showed nothing. maybe a reset would kick the thing back in line? but if a "reset" or reboot or whatever causes it to immediately start behaving again...what could be the cause of the problem? I mean if the actuator or door were malfunctioning, wouldn't it just not work? how can it work, then suddenly in the middle of driving fail like that, then go back to normal after a restart?

 

Good question? I have no real answer. If you can figure it out let me know, and everybody else that has that problem.LOL I know mine was like that for the summer , trying to get cool air. Now that we are in the sort of winter months, it seems to be working fine, with no codes or problems. I know when it was a pain, I would reset the DIC (while driving) and hear the actuator move to where it should go ( because I got cool air like I wanted), and then randomly go back to the heat? Drove me nuts! I usually had to stop, shut off the car, reset the DIC, and restart the car, Then it would stay? I am just thankful that its not summer, and I can just enjoy the ride as we don't get much bad weather in Dallas in the winter. I use to get the H codes, did a reset, and sometimes they would come back and sometimes not. Very random. But, I have not seen any now for a while, just lucky? Just hoping that I don't have to revisit this next summer. I wish I had a better answer for you, and maybe someone does as there are a lot of very bright people on this forum. (not me though, just a rookie). LOL

 

Does your internal temperature report normal or semi-accurate? What about the outside temperture indication? There's a vacuum line from the rear of of the intake at the MAP sensor that runs down behind the battery to the firewall. Are you sure its not broken, cracked or otherwise? Under the dash, that same line connects to a vacuum tree for lack of a better word. Have you looked under the passenger side to insure the lines are connected?

 

The only thing I can think of is that maybe the wire connection to the actuator itself is loose just slightly..it shouldn't be corroded.

OR your AC head unit itself could be taking a dump..I would think this should eventually throw a code but possibly not.

If your HVAC/defrost is all working good on the driver side but nothing on the passenger side. Then you restart and all is good. Then the problem comes back...it's not vacuum.

The only thing that separates the driver side from the passenger are those actuators (besides ducting of course) and the control from the head unit itself.

A battery disconnect or fuse number 27 pull is the same as a code reset for the HVAC

 

It has taken me a while to look into this at all due to snow.

I took the car out again today, it was about 10F

removing the fuse overnight did not appear to have an effect. clearing the DTC's didn't either. my first leg out to the grocery store the passenger's side appeared not to work at all. it was blowing cold air in almost immediately.

on the way back I noticed it blowing warm air as it should, for about 10 minutes, then it went cold again. the last several times it has been pretty much the same thing, it will work for about 10 minutes then fail. what could that be?

I have also been hearing some odd sounds from behind the dash. it sounds like something is trying to manipulate the blend doors or something. I sometimes hear a high pitched whine when the ignition is on. I believe its related because when I cleared the codes while I was hearing the doors moving I also heard this sound periodically, then it would go away. could it be one of the actuator motors? today after it turned cold I turned the seat heaters on and the AC off, I was hearing a rapid tapping sound coming from somewhere behind the dash. any clue what that could be?

it looks like I might have to do this the hard way, can someone give me more information about this indexing procedure, moving the gear a couple of teeth? or is that not applicable because I don't have the same codes? I'm not sure where the passenger's side one is. or does anyone know where in the shop manual info on this is?

clearning the HVAC codes while driving (Carefully) also did not have any effect, it stayed cold. I did notice two codes this time however. I moved the car once while the fuse was still pulled, so I wonder if these codes are just because of the ignition being turned on while the HVAC fused pulled.
B0441 H
B0446 H C - wondering what's up with that, the code is marked current, but at the time the fuse was back in.

also, I have reason to believe my battery may be on the way out. labored starting. it always starts so far. but I left it sitting for about a week.5 and checked the voltage and it was down to 10.2 or so, which is way too far for it to fall while sitting for such a short time. I charged it up but according to the DIC ignition on, engine off voltages right after taking it off were 11.8-12.2, which is probably a bad battery, its a 4 year old optima yellow. I know C5's react very badly to weak batteries, but would a weak battery still have an effect even while the engine is running? should I get that done before even thinking about going a step further with this?

tia!

 

so B0446 indicates right actuator out of range, I guess it needs the gear turning modification or replacement. someone please tell me I can get to it without major digging. I read somewhere the shop manual says to remove the whole dash to get to it. but it said the same thing about the flasher. looking for guidance here! I sure hope this isn't too difficult to get to.

 

I haven't had to do this, But, everything I have seen on the forum says the dash must be removed to get to it. Do a serch, there are some good directions with pics on how to do this.

 

anyone else have any opinions? if I have to dig into this I want to know I'm doing the right thing.

looking at the service manual I don't see any way to get to it without removing the dash. on the driver's side there's clearance, but its right behind part of the dash's structure on the right side. actually looks like an easier job than I had thought at first, I mainly worry about the tons of aftermarket wire runs I've made, I sure hope I didn't run wires through any part of the dash where there's no way to get them out but cut and splice them back afterward.

I guess here's what I need to know from this great community of people with more experience than me!

is getting to this thing inevitable at this point thus the dash pad needs to come out?
should I replace the actuator or try to rotate the gear a couple of teeth, which way if so? I don't see a write up about the passenger's side.
if the problem is "indexing" because of the blend door flexing over time, wouldn't replacing the actuator alone not fix the problem? wouldn't the gear rotation be the ultimate solution?

is there any way to tell without getting in there if the gear is actually broken or if its the door flex causing the out of range error.

for other projects I've had the cluster out, radio bezel, console, glove box, and the driver's knee bolster. according to the manual the dashpad is just another couple steps farther. anyone ever done that before? is the shop manual procedure the best to use or are there any unofficial "tricks" to make it easier?

 

Anyone? I'm sure I'm not the first person who ever had to take on the passenger's side actuator...or removed the dash pad. I'd really like some input from someone who's been here before.

 

pretty please?

 

Hi mcgilles, try looking at this post, I used it to pull my dash for a HUD install.


http://forums.corvetteforum.com/c5-t...d-install.html


Good luck and post results as I'm getting codes 0361, 0363, 0441.

 

Ok. Really hoping for more help on this.
I successfully pulled the actuator out and rotated the gear 2 teeth CW assuming that on the pass side I'd need to go the opposite direction from what works on the drivers side.
It worked all was perfect for about 6 weeks then it failed again this morning. No warning, worked then 1/2 way to work cold air pouring in the pass side. I'm pissed to say the least. No codes, reset and restart did not fix it.
I can get to the actuator, but I don't know what to do once I get to it. Please help! I'm desperate and frustrated.
Thanks
-mike