FAQ: Warm/Hot Air on Drivers Side, Cold on Passenger Side

Welcome Rick, this write-up was taken from the fourth page of this thread...

Ryan from Ohio wrote:

Ok Guys, this is for my 95 Rivi. Im not sure what year they changed but the writeup depicts something different then what we have...

This is with the glove box and the computer stuff out of the way,


Some shots of the servo motor location:


The servo motor out of the car:


Opened up:



Pull the missing gear out to turn it easier. Note you need to align the blue gear as shown in the next pictures (I think?):


The correct setup- I think. Its working right. When I plugged it in but not mounted, I went from 60 to 90 degree's. The servo didnt bottom out/bind up. Seemed to be centered well.

These are the pictures for that condition:



What I did was simply clean the crusty hard grease out of it. Cleaned the gears. I only used grease on the shafts and the worm portion (at the motor). Plastic gears dont require to be drowned in grease, they are self lubricating.

I dug into my dash AGAIN this last weekend...to see if I could figure out WTF was wrong. As you guys, I get warmer air from center and nice cool air from passenger side..

I took off both actuators for the air mix (driver's and passenger's).. I can turn the passenger doors manually and they'll change to hot/cold.

I can turn the driver's side doors manually and they go to hot/coolish...

I have a camera which is designed to look into tubes...and I tried to get a better look inside. You can gently remove a tube which connects to the main airbox assembly on the drivers side which connects to that tube which gets the interior temp (right by your right knee)...and looked in there....but couldn't determine if door was broken, stuck, jammed... It turns fine.

Sticking my finger in that hole I could feel the tip of that driver's side door and it's a flexible rubber like material on the end (the shop manual shows it as "L" shaped at the end.
See the #2 door...that L shape...it's hard to descibe, but that is a flexible rubber material



I wonder if over the years, maybe a bit of that rubber has eroded, or broken off. So no matter how tight the seal is against air going around the heater core is never 100% shut off...

I gave up and put it all back together... Besides ripping it out entirely I see no fix...

G dangit I was hoping you would have found the problem. I'm with you on this one. I just don't have the time to tear apart the whole dash/control assembly to remedy the situation. Thanks for the replys.

Nate did you disassemble the actuator and look for broken gear rings? That's typically the problem - the actuator itself.

Behind the glove box there is a part of the dual zone climate control that you can disconnect. I don't know the exact name but if you unhook it, the main will take over that side but your temp display will flash. Cured mine!

Somebody has to come up with a fix for this. Does anyone have any pic's of the hvac unit out of the car? I'm thinking that the only way to fix this is to pull the unit out but what a major PITA! It's 90 and humid as hell today and I sure would like some cold air on the drivers side.

Sorry, I've been out so long

Mine still blows warm in the middle vents (and driver's door)

At first, I thought perhaps the door wasn't closing enough, and air was going around the heater core and I'd get "warm" air instead of the pure A/C air. But I don't think I'm getting any hot air...just ambient air...

It seems my center vent blows ambient air. After awhile, it'll blow cool air as the interior air has been cooled by the passenger vents.

So how can this be? I can verifiy my recirculate door is closed, and I'm only circulating interior air, but the center vent acts as if it's just moving non a/c air...huh??

What is this unit behind the glove box which deactivates the dual zone? Can we get a pic?

It was only 80 today, but the car was tepid...that's not acceptable!

Anyone??

Hi guys. This is my first post, but I've been following the forum for years.I have a '95 Riv that I bought in '97, and still under 100k and looks almost mint. Bright White with Dark Ruby interior.

So. Last summer I had the same problem, right side cold, left side hot. Read all the thread here and looked at the door actuators.They didn't look like anything I wanted to mess with so I kept investigating. I found another site that had a take on the problem I hadn't seen before. Something like dual evaporator coils and when refrigerant gets low the system shifts the work to the passenger side. My terminology may not be correct but that's the gist of it.

I'm really surprised nobody suggested adding a can of R134a. That's what I tried and it's been blowing cold on both sides for 2 summers now. I hope those doors never go out on me because I really don't want to get in there. Too old and not too agile!

Bob

That's the first thing that came to mind several years ago when I noticed the problem but my pressures are right on the money. I have never heard of the dual evap coils whereas the Riv does not have that style of system.

faxbob64 wrote:

Hi guys. This is my first post, but I've been following the forum for years.I have a '95 Riv that I bought in '97, and still under 100k and looks almost mint. Bright White with Dark Ruby interior.

So. Last summer I had the same problem, right side cold, left side hot. Read all the thread here and looked at the door actuators.They didn't look like anything I wanted to mess with so I kept investigating. I found another site that had a take on the problem I hadn't seen before. Something like dual evaporator coils and when refrigerant gets low the system shifts the work to the passenger side. My terminology may not be correct but that's the gist of it.

I'm really surprised nobody suggested adding a can of R134a. That's what I tried and it's been blowing cold on both sides for 2 summers now. I hope those doors never go out on me because I really don't want to get in there. Too old and not too agile!

Bob

I can't find the previous post but I have also read that a low system will cause these symptoms. I too am not too sure about the "dual evaporator coils" but I did read somewhere that a charge did fix the problem for another member on the board. Even though your pressures read correct it might be worth a try to see if adding "some" refrigerant might help? I remember it seemed to help adding some to my ’95; it might not have corrected all of the temperature differences but somewhat?

Just my $0.02 worth ...

I hooked up a can lasts year and was low, but frequent checks since then still show it in the correct range.

But, good ?? Do we have a dual coil? And if so, could a "clog" in one make it warmer...it's just not getting flow through it? If so, is there a method to clean it out? Vacuum the system then recharge?

And also, does the heater core always get hot coolant? I originally thought door wasn't closing to heater path, and the warmer air was actually hot coolant air...but I don't think that now... Like I said, I just get tepid ambient air...and as far as I can tell, that door is closing...I've taken both actuators off and manually turned them with pliers....full range, just didn't get hot.

Pain in the butt I tell you that!!

guys, drove it today, and warm in center again.

I'm just not convinced it's the actuators. I've known for awhile the compressor is bad. One day there was a drop or two of a/c oil on the drive and bottom of compressor. So I refilled...but a leak is a leak...

So, I'm going to buy a new a/c compressor and have the system drained and recharged after it's in.

I did see a post, of a guy with a 98... he said once he put in a new compressor, and charged the system fully, the center vents were fine. SO... I think a new compressor/a fully charged system will solve the problem...if not...I still need a compressor since my old one needs changing...

I'll update when that's done. It's too hot TO NOT have a/c in my baby!

Nate, sorry to hear you have to bite the bullet on a new compressor but for sure post when you are done so I can stop racking my brain trying to figure this out as well.

Paul

I was told to replace my accumulator when I change my compressor. so I ordered that and the condenser just for good measure! looks like its going to be a bitch to change the compressor.

Glenn bro,give it to a pro to do it for you,it'll take him 1.5 to 2 hours only and that's that.Dealing with this goddamn AC yourself will ruin you day.......man...................!

I will, I've seen two instances in Google searches whee a Riv guy said he replaced the compressor and then it blew cold...
I think the main part is a fully charged system...but I wouldn't be suprised if the compressor is not fully compressing the gas that it wouldn't get so cold....
...think she's going in in a couple of weeks..

I'll keep all posted.

Some of you may onto something with the "low Refrigerant" statement. I have the same issue some of you are having where warm air blows on the drivers side and cool air on the passenger side of my 98 riviera. About 2 years ago I replaced my radiator and I accidentally released some of the refrigerant because I thought that unit also had to be removed. Maybe I will try a recharge before I mess with heat/cooling vent doors.

Wondering if any of you could help!

I have a 98 Riviera Supercharged & I am plagued by the "Warm Air On the Drivers Side" "Cold Air On the Passenger Side" problem. I read somewhere that recharging the refrigerant could solve the problem but it has not. Here are a few of the symptoms.

- The Exterior Temp Gauge was ripped of during a small fender bender with a snow bank.
- My HVAC unit flashes the Interior temp
- Only the Passenger side gets cold, The Center Rear & driver side vents all blow warm air.

Would having my Ambient Exterior Temp sensor removed cause this problem? If so please explain.

Any help would be greatly appreciated.

It has to be a blend door not working properly. When I get time I'm tearing into mine, I can't take it any longer!

I tore into mine as best I could...
the question is...why is it warm? Is it not closing off the path past the heater core? And that warm air is a mix of hot and a/c? Does the heater core always get hot and it's closed off normally by that vent door? My recirc door is closed for sure!

If it is closed off, then the warm air can only be there's not enough refrigerant to cool the entire condensor (is that the name?) so it never gets cold enough to blow cold air.

Either way it sucks. I'm going to get my system vacuumed out, then refilled properly, then I'll see what happens.. the guy at Menieke tried to say the refigerant breaks down to 'air".. untrue.. it's just a gas which undergoes expansion & compression...which heats and cools it...it never breaks down.... but it can leak out!

Nate try this, while driving make sure the temp is set to 60 deg and then turn it off with the windows rolled up. Feel the warm/hot air coming out of the rear of the center counsole vent. On the Riv, the heater core always has heat going through it so that means there is a door in there somewhere not closing off the cool air being blown across the evap coil mixing with the hot heater core air. I really don't think it has anything to do with low refrigerent. Lets face it, when a car is low on freon the compressor usually never kicks on anyways.

when my 95 began showing the same signs,I listened very closly to the system.I figured when I heard the ac doors strugling to open and close once they were,that the plastic gears were bone dry.I popped off the dash and greased up the plastic gears with moly lube and the problem went away.moly lube is not what youre supposed to use on plastic gears.Its all I had though at the time.there is a special for plastic lube thats clear or a clear green.Honda makes a super cool clear green lube thats super expensive but works fantastic! lasts for years.

I'm not sure that's true.

It's ambient...not hot air. When I start the car up, it blows ambient on drivers, cool on passenger. About 15 minutes into drive, it'll start blowing cooler from drivers as the entire interior is cooling down.

I've been in the actuators and moved the door all the way from one position to the other and it got hot and back to ambient.

I'm not convinced it's the door or something else. I can't imagine a clogged evap coil...but I do know I need to vacuum the system, test for leaks and recharge...then go from there.

Cause the last part is tearing into it full time...

The gears are lubed too...

it sure is a pain though!

Harbour Freight sells a ac gauge set for around $50 bucks.that would tell you just about everything you need to know.Thats half what you would be charged at the shop

I have a similar problem to what Nate is describing.. I recently recharged my system (there is no leak). Can someone tell me if not have an exterior temp sensor has anything to do with my problem? I am talking about the sensor that is mounted underneath my radiator support!