My 98 was blowing hot air on the passenger side, as well as throwing codes to indicate a faulty actuator.
I should state that it's a dual-zone climate car.

The HVAC codes I had were:

B0446: passenger's side HVAC actuator out of range
B0367: Right Actuator Feedback Open
B0365: Right Actuator Feedback Short to GND

I've owned the car since 99 - this has been coming for a long time.
At first, a reset would fix the problem.. but it would always return.. This time, the reset failed, even after 3 tries.
Since it was the passenger side, I decided to remove the dash and replace both units.

After reading several EXCELLENT threads on this I decided to purchase the Dorman units (PN 604-106 for dual-zone), $75 each on Amazon. I believe the manual climate units are different (and less expensive).

I was dreading the dash removal.. I'm very comfortable with wrenching on the powertrain.. but I HATE interior work. I usually break something.
But I followed the excellent directions in this thread (https://www.corvetteforum.com/forums...d-install.html)
It took about 2 hours, but was not too bad. I thought the worst was over. It wasn't!

Actually getting to the actuators is a real pain. Especially the driver's side unit. I had to disconnect some air pipes that run through the area.
They are 23 years old and fragile.. All went well. Probably another 1.5 hours getting both actuators out.

As expected, the passenger side had a cracked gear inside



Oddly, the drivers-side actuator was a different type (same MFG, but different design). It was still intact, and probably working fine... But I wasn't going to leave a 23 year old actuator in there!



So I'm just waiting for Amazon delivery now... then hope I can remember how it all goes back together!
It's intimidating, but my advise is don't fear this job... It's not as bad as it looks! I understand it's a $1200-$1500 repair from a shop. It cost me $150.




Thanks to all who contributed to the wealth of knowledge on this topic over the years here!

Fred

 

On the way back together, remember that the screws vs. holes is different between driver and passenger side. I spent more than an hour trying to get the second screw into the wrong hole on the passenger side actuator...
Also, since you're already waiting on Amazon, now would be pretty good timing to go with that double din radio you've been thinking about.

 

Good work on the actuators! Not as terrible as it looks. Surprisingly, the dash comes off quickly. I did it and was glad to save the price tag from a dealer or shop. The trick I had to discover on my own was to cycle the air on the dash to move the actuators into place so they would fit.

 

Thanks Jim. The actuators arrived and I'm about to try to install them. I was wondering how to "align" them.. as I noticed the new units are "parked" in a different position than the old ones.
Wish me luck!
Fred

 

Fred, I couldn’t find anywhere on the net to help me. I didn’t want to mess with the gears and wreck the new actuators. After almost giving up a few times, I finally realized changing the temperature would change the position. It worked. I should’ve guessed that. Or I’m just not meant to be mechanic. Good luck. You will have a great feeling of satisfaction when you’re done. And save $1500.

 

All is back together and air is working perfectly.
Rather than force/turn the actuators (I agree with you that is a bad idea!), I found I was able to turn the shaft of the air doors to line them up. They then slipped right onto place.

Enjoying a cold one after this very cool project. Pun intended!

 

Nice write up! I just test drive a 1999 today that had this same issue. First thing I noticed was the passenger side was blowing cold but the driver side was blowing cool and not as much. It was also throwing code P0410 which I found another write up here that is a vacuum leak. All of this combined describes what I was experiencing. Air blowing out of all vents no matter how it was adjusted and less and warmer air on the driver side compared to more and cold air on the passenger side. I doubt the dealer will fix it so maybe I can negotiate that into the deal.

 

Many times on automatic climate controlled cars, and not just the C5, the passenger side will blow slightly to obviously colder than the drivers side because the system is low on refrigerant.......

 

Also good to know! Thanks for that info.

 

I would love to hear some logic on that. Not saying it can't happen, but why on earth would it?

 

I too am dubious of this, but there are many threads claiming this. I wonder if it's a matter of the AC reset "fixing" the blend door actuator? Maybe fooling some into thinking it worked.

I think the best advise is to pull the codes and work back from those.

 

Anyone know a shop in SC,NC,GA or VA who would do the actuator replacements. C&S Corvette in FL. does it for around $800 or so.

 

Don't know why it happens, but when I first got my C5 the driver's side vents were noticably colder than the passanger side. C5Diag helped me with it and added some Freon. That fixed the problem. So it's an anecdotal story. Maybe it was a coincidence but 3 years later it still working.

 

Just to add a small 0.5 to this (not that there’s much of an antidote), the OP’s experience was otherwise very close to my own. One difficulty I encountered was one of the old blend doors being pretty well stuck onto a shaft. You’re worried about the old white plastic breaking because it’ll have become brittle over the years. I used some penetrating oil on it and it did detach but it wasn’t easy.

 

I dont have the answer, but it is true. Same thing on my old '03 LeSabre. Someone somewhere told me it needed a 134a charge. Sure enough, both sides were cold after 1 can of 134a. I got cooler with 1 can, myself, but NOT 134a!!