A/C Fan runs all the time

[alvinator]

We store our 1993 LY 33 in a covered storage facility in South Florida. The facility provides 30 amp electric.

We set our A/C on low and about mid point on the dial to prevent mold from the high humidity. But the fan doesn't shut down when the compressor has done it's job. It just runs and runs like a Timex!

Is there a fix for this?

[mprokop87]

In my Argosy I have a newer Dometic AC unit and mine does the same thing. My controls are on the unit cover in the ceiling. To my understanding this was how it was meant to work. Now my parents have an AC unit in their new trailer that has a thermostat on the wall and theirs will shutdown when the interior has reached the right temperature.

So, is yours supposed to work like mine and run non stop? If not, it sounds like you have an issue with the thermostat. Can you try putting it on heat and see if the fan for that runs all the time as well? Its possibly that you have a dirt switch or relay in the thermostat and its causing it to constantly have a connection. If you have access to another I would try swapping it out to see what happens.

Matt

[AtomicNo13]

Assuming you have the original Penguin installed, some run all the time, others cycle on and off. I called Dometic many years ago and got instructions on how to change this. If I recall it requires the removal of a solder bridge on the circuit board behind the inside control panel. Anyone with slight soldering skills can perform this mod. I don't have the PDF they sent with me as I am on the road, however I need to clean my unit and I can take some photos and do a little how to for you.
Personally, I think the on off of the unit makes more noise than the constant blow of the fan. You could wire a simple switch to select between the 2 choices.

[Skater]

Mine has a high/med/low/auto switch. If I remember correctly, in auto it cycles the fan on and off. In high/med/low the fan runs continuously.

[alvinator]

Ours has the controls on the ceiling unit. I'll check for the auto setting first; I may have overlooked it.

[AtomicNo13]

I think the auto just controls speed not on off.

[alvinator]

I checked and I do not have an auto setting on the controls.

[overlander63]

The modern Penguins with the remote thermostats have an auto setting, and the fan will shut itself off if placed in that mode. Any other mode will cause the fan to run continuously, and in some cases it will even run when the furnace is selected.

[92landyacht]

Ya, my 92 LY with original Penguin AC leaves the fan on all the time. It does have an auto setting but the fan still runs.

I would be interested in the jumper modification that turns off the fan as well.

[idroba]

Most of the older units ran the fan constantly and the thermostat only cycles the compressor. Just the way they are designed. One of the reasons that was done was because the constant fan running allowed the built in thermostat to be more sensitive to the actual temp in the rig. Without the fan running full time the temperature control accuracy was poor (thermostat up inside the AC shroud). I am sure that someone could come up with a modification to change the fan with thermostat setup, but it would need some knowledge and skills.

Some of the newer units have the fan off with compressor feature built in.

I have one of each, my old Emerson on the '74 Argosy runs all the time, the Dometic on the new FC has the option of either constant run fan or cycling fan.

[Pat Conway]

In our 1988 the fan runs constantly also, and to tell you the truth, I like it that way. We have been in the heat of Texas where it was over 100 degrees F in the shade and you want to direct the airflow right on you and hope it keeps blowing. Just like idroba has said, it creates a more even temp throughout the trailer with the fan continually on. When the time comes to get a new A/C unit I'll be looking for another one that is constant fan also, and I hope they still make them. After awhile the A/C noise becomes more of a "white noise" and you won't notice it that much. When the airflow stops, I get hot in a hurry, and my wife will be even more miserable.

[drboyd]

If your aim is to reduce moisture in the coach, run the fan only when the compressor runs. If you run the fan constantly, the condensate on the evaporator coil re-evaporates into the cabin air.

[RocketManKen]

You have fan set to low, which will run on low. If you want it to cycle with compressor, set to 'auto'.

[AtomicNo13]

Auto will never shut off the blower on most of the older Penguin models. Auto only switches between low medium and hi.

[DaveFL]

Would like to have the option of complete shutdown, but ours are 3 speed always on, found once area is cool it is doable to change to low, alternative is to run the a/c not where we are, living area or bedroom, when one can handle it. That only happens when we are in a shady spot, full sun and it has to run, to keep up and move air for comfort.

[rbg46]

Found this thread this afternoon while researching the "fan doesn't turn off" issue for our 2016 FC 19. Until early this morning the fan would shut off when the compressor cycled off. We have the Dometic with ceiling ducts. the remote thermostat is set on Auto, but the same thing happens in a/c mode.

Guess it'll be off to the dealer Monday since we're still under warranty.

[Mike1997]

My 97 Landyacht has the two original Duo-Therm Penguin units made by Dometic. I have a single wall t-stat that controls both and it has auto mode which makes them cycle off-on as needed.

[LaBigDogs]

Originally Posted by rbg46

Found this thread this afternoon while researching the "fan doesn't turn off" issue for our 2016 FC 19. Until early this morning the fan would shut off when the compressor cycled off. We have the Dometic with ceiling ducts. the remote thermostat is set on Auto, but the same thing happens in a/c mode.

Guess it'll be off to the dealer Monday since we're still under warranty.

I have the same issue.... what was the fix?
Thanks Mark