Hi. I hopped in my 1997 C5 today and switched on the AC to cool things down. I noticed that the AC out of the passenger vents was quite a bit colder than the drivers side. I've read through the threads about the Dual climate control C5's having issues and the actuators being a problem...
My question is, My C5 has the Manual type/single zone HVAC controller. Does my car come from the factory two duct actuators for the Dual zone option? Or is there a single actuator for the base model single zone HVAC cars?

I have a feeling I have an actuator problem on the drivers side.

 

Manual Control systems have only one temp control actuator. The attached diagram should aid in understanding the system

 

Thanks for the diagram... I replaced the vaccum supply hose a couple weeks ago, to get all the vents working corectly and I tried pulling fuse #27 to reset the vents. Still cooler on the passenger side.

Any ideas why air would be cooler on one side or the other with a single Air Temp actuator system? Inline filter? Gremlins?

Another question...
Can anyone tell me the correct replacement blower motor controller part number and where to get one? I was given the Napa Auto parts replacement and it worked but only on speeds 1,2,3 and 5. Position 4 the motor just stops... Are there 2 replacements? One for 4 fan speed cars and one for 5 fan speed cars? I have option C60.

The part number of the one I pulled out is #15304891 Date 5/09/97 REV. C... The Napa upgrade I was given is Napa part number BR77. I've tried 2 of the Napa controllers thinking that the first was just bad out of the box. Both had a dead position 4...

 

Hmmm. I have noticed that my passenger side blows noticeably cooler than my drivers side as well. I have a 98 with the manual hvac unit. I haven't tried anything yet. I am pretty sure I need to replace the refrigerant anyway.

 

By far the most common cause of this is that your system is simply a bit low on freon,do a search.

 

Just had the system evacuated, pressure checked and refilled. 1.65 lbs of freon. Passenger side blows Ice cold...

 

With 1 actuator for the climate control, does that mean there is only 1 door to control the flow/temp?
My thinking is maybe a door isn't closing all the way on the drives side or the foam seal is bad or blocked from closing.

Also is the actuator located on the drivers side or passenger?

 

Temp control door is electric, as is the blower of course. All other functions are vacuum actuated.
If you have a complete or partial loss of vacuum, your "mode" door will not work or maybe only partially move as will the other two vacuum motors. The vacuum source is on the other side of the firewall and the small nylon supply line comes off the vacuum reservoir tank. Not surprisingly, this all sits directly under the battery tray, so..............has your battery ever leaked? Not that would EVER happen on the early C5s, right?

 

Oh Ya..! I've been down that road and replaced the nylon line with 3/16 vaccum hose and wire ties on both ends from he manifold to the vaccum canister behind the passenger side fender. That fixed my non moving vents.

I'm going to borrow an Animometer from work and check to see if the air flow from the drivers side matches the flow of the passenger side...

 

I bet the drivers door air flow is less than the passenger vent. It seems to me the ductwork makes it much easier for the air to flow out the passenger side than out the vent on the drivers door.

My dual mode system seems weaker on the drivers door compared to the other vents. Even working right and recently charged. The drivers door was useless when it got low on refrigerant.

 

The attcahed pdf gives the design airflow percentages at the various registers with various settings, May help in trouble shooting

 

With the single zone manual control if the airflows are approx correct, you can check the supply air temp to verify cooling system operation.
The attcahed pdf shows what the supply temp (at the center grill) sholuld be at various ambient temperatures and coincident RH conditions.

 

Ok... So I decided to take the dash off and see first hand what was going on inside my HVAC Duct Box and see if all the doors inside were moving as described in the drawings above. Also I figured I'd give the dash, windshield and pillar covers a good detailing while I had everything out.

So, I Was able to look inside and see everything move and was content with the condition of the seals on the doors, but could tell if the Temp control door was sealing all the way. Verified that there is only one actuator controlling the temperature... (Thanks) I removed the actuator and reached inside and held it down by hand. just to make sure no warm air could seep by... Ran the actuator back and forth to make sure it would travel lock to lock and to check for any grinding or clicking. Here are the pics.





While I had my hand in the ducts I noticed that the mesh in the in the rear was only cold on about half of the passenger duct and warm all over on the drivers side... Can You say FREON?
Picked up a can of of the stuff with it's own gauge atatched and hooked it up. Ran the AC full blast for 3 or 4 minutes. The gauge read charged but was on the low side of full. 25/26 pounds showing on the gauge. Decided to give it a squirt and see what it would do... The gauge went to 35 pounds and things started cooling a bit better. Decided to give it a little more and took it to the high side of the filled mark... All kinds of cooling on the passenger side and the drivers side was actually cooling really well... Still not like the passenger side but it's cold enough for me to live with it...

Thanks Everone for the input... Ice is Nice!!!