Improvement in Front HVAC air flow

[Richard and Rhonda]

I have a unit originally supplied by Frigi Cool out of Dallas. Frigi Cool was acquired by SCS Frigette. Frigi is long gone, and SCS doesn't deal with this kind of business any longer.

The air flow from any of my dash vents or defroster was abysmal. Non existent practically. In addition the fan would speed up dramatically from time to time when I hit a good bump.

I finally got to this one on the list, and I apologize up front for no pictures.

I removed the front console completely. I had to unhook the leveling, rear camera, and some other connections to move it out of the way. Once it was removed I was looking at the snakes nest of large diameter hoses that connect the unit to the AC vents, foot vents, and defroster vents. Like most auto heat control units, the control panel sends vacuum to different vacuum actuators to open and close air control louvers. The opening and closing of louvers controls where the air flows. My biggest problem was that the air came out of all the vents simultaneously, without regard to the button selected on the control panel.

I thought that I would find that the vacuum level was weak or the vacuum actuators were broken. Wrong. What I found was three different problems that all added up to the lack of flow. First, the louvers use soft foam to seal when they shut. The foam was old and wasn't really sealing. A trip to a fabric store and the foam was renewed and some thickness was added where needed. I thought I was finished. When I reassembled the air flow box, I noticed the louvers didn't move freely. Turns out that both if them had parts of the louver that touched the side of the air control box. A few minutes of Dremel tool time fixed that. Then I noticed that the doors didn't completely shut because the stroke of the actuator and the needed stroke weren't matched. So some washers and spacers to correctly position the actuators was in order.

The fan speed issue was caused because the fan motor was grounded to an aluminum plate on the front wall of the coach. I ran a clean and know ground to the motor.

Result.............Holy cow, real air flow. Real air flow out of the vents I choose. It blew my hair back. Wait that's an exaggeration, I don't have any hair.

So, if you are experiencing similar problems on a mid 90s coach, you might want to look into these issues. The air control box was poorly made as it came from the vendor. The issues I saw were not things that developed over time. The good news is that they were easy to correct. Better than new now.