AC Mod gone awry?

[OldKingKibitzer]

I recently re-taped/sealed my AC return and outputs...I also sealed off the vents that are on the main housing/cover as my unit sits in the garage of my Fuzion above the happy jack and just blows cold air straight down onto the top bunk...So my thinking was that would help divert the air into the ducts that are there and help to force more air out of the vents in the rest of the trailer. It seemed to do just that until....

Today the rear AC is very very quiet and does not seem to be blowing as hard as it had been. Did I do something to mess it up by sealing off those rear vents? They are able to be closed off completely from factory and have been closed for months. Or is there something else going on here- Not enough amps (Hooked up to 50amp but who knows) or the AC is slowly dying...Any input would be appreciated!

PS- Front AC is blowing 51 degrees and rear is blowing 62 degrees.

[JRTJH]

This is just a "WAG" (Wild Amazing Guess)....

With the vents restricting airflow through the evaporator, I'd guess the unit may have "frosted up" or "frozen". Turn it off, let it sit for a couple of hours and turn it on again. As soon as you turn it on, check the airflow and see if it's closer to what it was "before this event".... I'm guessing it'll be "back to normal".....

[OldKingKibitzer]

This is just a "WAG" (Wild Amazing Guess)....

With the vents restricting airflow through the evaporator, I'd guess the unit may have "frosted up" or "frozen". Turn it off, let it sit for a couple of hours and turn it on again. As soon as you turn it on, check the airflow and see if it's closer to what it was "before this event".... I'm guessing it'll be "back to normal".....


She's off now and I'll wait to see what happens!! I may have sealed it up too good!

[JRTJH]

Typically, on days when the humidity is high and the temperature isn't too extreme, people will run the A/C on low fan speed (to reduce noise). If the humidity is high enough to cause excess condensation on the evaporator coils, that moisture will collect and freeze, effectively blocking the airflow. There's a "freeze plug" detector inserted in the evaporator, usually about 1/3 of the way from the top. It's connected to the control box and if it senses icing, it will idle the compressor for a bit (until the temperature rises enough at the evaporator) to prevent icing. Sometimes, just running the fan on low is enough restriction to cause icing. Sometimes shutting a vent or two will cause the problem and sometimes the freeze plug will fall (or vibrate) out of the evaporator coils and fail to detect icing. When that happens, the compressor "chugs along" until the evaporator is completely frozen over and all airflow stops.

It sounds like you may be experiencing one of those situations. My guess would be the limited airflow from closed vents. You should know in an hour or so.... Let us know how it goes.

[OldKingKibitzer]

So I let the AC sit for a few hours and it seems to be running a bit stronger but still isn't where it was. It could be just my perception as of right now. It is pumping much colder air. We're currently in the desert and it's in the 90s with sun and no humidity to speak of so I was surprised it froze up if that's what happened.

I'll have to check to see if the freeze plug is there/functional...I have cleaning the fins/coils on my list of projects.