Hi Russ,
I have not worked directly on the low-profile Penguin 6003 series AC units, but have on the larger Brisk Air units.
This may help you sort out your problems.
Here are two resources that may help if you do not have them. These are now loaded in our FILES section and you can download a copy.
The 6003 series install manual,
https://www.sunlineclub.com/forums/d...o=file&id=5650
The larger BriskAir year 2000 service manual.
https://www.sunlineclub.com/forums/d...o=file&id=5649
Those are direct links to the file locations, and the FILES section has a lot of good information on other items. See the FILES tab at the top of the forum, click it, and read on.
Rest assured, the low-profile 6003 series works in a similar way to the larger BriskAir units. The only difference is that yours is made to a lower profile, designed not to protrude as high on the roof. It's what they call a 'non-ducted' AC system, meaning there are no long ceiling ducts with ceiling air registers along the length of the camper. All your air comes out of the central ceiling grill/register. The smaller campers had the non-ducted, and the larger campers with rooms had the ducted systems.
The AC system has a roof unit, the unit up on the roof, and an Air Box between the rooftop and the ceiling inside the camper. You see the grill of the air box inside the camper.
Then there is the control system; in your case of the non-ducted, you have the mechanical controls, and the whole control system is housed in the air box area.
I gave the above info, so reading the manuals will help better explain what language Dometic uses for your system.
As you have sorted out, the controls on the mechanical system are simple. The fan control is the knob selector switch, and the compressor has high, med, and low, which is the fan speed for the cooling mode, and it allows the compressor to run when the T stat calls for cooling.
The T stat is an all-mechanical device, the sensing tube sends a signal to the switch inside the T stat to turn on or off the compressor based on temp. NOTE: I'm going out on a limb here, but I'm assuming Dometic uses the same mercury tube-style T stat on the Penguins as they do on the non-ducted Brisk Airs with mechanical controls. The T stat only works between 65F and 90F—page 14 of the Brisk Air service manual discusses this. If you are testing the system, the ambient air must be between 65 and 90, or the compressor will not run. I ran into that once in my shop in the winter. I had to blow a small heater on the T stat to warm it up and run the AC on the bench. The shop was at 55F, and the T stat would not turn on.
Since you are getting puffs of cold air, you may have lucked out; the gas system is working, but the T stat may not be. The T stat is a simple on/off switch to the controls. If you jump the T stat out to be on constantly, the compressor will run non-stop when the fan switch is set to cooling. If you try that and the system keeps pumping out cold air, the T stat is bad, or you are out of working range. They do sell the T stats. Dometic may have stopped selling them, but I bought an aftermarket one, and it looked the same as the Dometic-supplied one, which they purchased anyway.
If the compressor is running non-stop and no hot pipe or cold pipe is going in or out of the compressor, then the gas system is the issue. These small RV AC units were never set up to be gas system serviceable. If a gas leak happens, the only way to repair it is for an AC tech with all the right gages and freon reclaiming equipment to cut into the system, find the leak, fix it if possible, and then recharge it. Most of the time, their labor and parts charges are high, and it begs the question, do you buy a new roof unit? Get all new motors, coils etc., for not much more cost?
And if you need a new roof unit, did Dometic discontinue your Penguin series roof unit, as they now have a Penguin II unit? And if it is anything like the Brisk Air II units, will the redesigned system not work with the old air box, and will you have to buy both the air box and the roof unit? I have yet to go down the Penguin Replace trail, but I have on the ducted and non-ducted Brisk Air units. A new roof unit will not work with an old-style air box. You have to buy both.
If you need a whole new system, I recommend you look into a Coleman Mach unit in place of the Dometic. Coleman Mach is still made here in the US; you can call them directly and not be a Coleman dealer, and they will discuss technical issues with you. They have a better warranty and many options for different AC sizes and styles. Lastly, I now prefer Coleman Mach over Dometic because of how they are built. I'm not overly impressed with the latest Dometic redesigned units. The older units were built well, but the new ones??? Yes, they work. Will they last the test of time? That is a good question.
I hope this helps. Let us know how you make it out.
John
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