Just picked up a really nice 2000 Lance Lite. Slight issue with the AC, it works TOO GOOD! It will absolutely freeze you out, and after it runs for a couple of hours, it will start slowing down to the point that it eventually overloads the Generator and shuts off. What I found, is that during this situation, the lines and the compressor are COMPLETELY covered in ice! Let it thaw, and it'll work fine for a bit.The info I found online says usually one of 2 problems: Condenser or evaporator are dirty (they are not on mine), or freeze sensor is shot. I can't find a freeze sensor on mine. I did find a picture online that shows a Duo Therm that looks just like mine, and there appears to be a sensor in the side on the (condenser or evaporator?, not sure which it is). Here is a picture of mine. You can see the hole on the left, but nothing in it. Also is a small plug down below that's empty. And also, there is a pink and a white wire that has been cut, just hanging. Can anyone with a Duo Therm around 2000 verify that I should have a sensor in that hole? And if so, does it plug into the empty spot down below?Empty plug down below:

the empty plug could be for an optional electric heat element.

I think you're barking up the wrong tree. Your AC should run until it reaches the preset temperature as determined by the thermostat knob, then cycle on and off as the temperature rises and falls.It should not be running that long, freezing you out, then freezing up. Initial run in a hot camper may be a little longer but once cooled down it should not run more than half an hour at a time unless it is severely hot and can't keep up. Since it is freezing you out, it obviously is not severely hot, and has no issues keeping up.The most obvious cause is your thermostat is not working. However, is it possible that you simply are not familiar with how an old analog AC unit works? As you turn the thermostat knob, the wider the line, the colder the setting.When I set my AC, I simply turn it to max cold, let it run until the camper gets to the desired temperature, and then turn the knob back until the compressor shuts off. Then it will cycle on and off to maintain that temperature.

If it ices over before it reaches the set point of the thermostat it's most likely low on refrigerant.

mkirsch wrote:I think you're barking up the wrong tree. Your AC should run until it reaches the preset temperature as determined by the thermostat knob, then cycle on and off as the temperature rises and falls.It should not be running that long, freezing you out, then freezing up. Initial run in a hot camper may be a little longer but once cooled down it should not run more than half an hour at a time unless it is severely hot and can't keep up. Since it is freezing you out, it obviously is not severely hot, and has no issues keeping up.The most obvious cause is your thermostat is not working. However, is it possible that you simply are not familiar with how an old analog AC unit works? As you turn the thermostat knob, the wider the line, the colder the setting.When I set my AC, I simply turn it to max cold, let it run until the camper gets to the desired temperature, and then turn the knob back until the compressor shuts off. Then it will cycle on and off to maintain that temperature.Hmmmmm.....There's not a thermostat, just the knob that adjusts cooler and warmer, maybe I need to adjust it down? I know it works, if you set it lower, the AC cycles on and off. It's definitely been hot here, I went into the camper yesterday in the middle of the day and the inside temp was 104 lol. Running the AC on high for 30 minutes cooled it right down, but it just keeps getting colder and colder until the temp in the camper is about 63. I will try the knob to see if it helps to stop the freezing up by cycling on and off.

toddb wrote:If it ices over before it reaches the set point of the thermostat it's most likely low on refrigerant.No thermostat, and it will make the camper COLD. It can be 95 outside, and the AC on high will get it down around 60 if you run it long enough. I'm going to try and adjust the Colder/Warmer knob on the AC to have it cycle to just outside air after it gets cold.

Need help with Dometic Duo Therm Air Conditioner

towpro
Explorer
Aug 12, 2020
the empty plug could be for an optional electric heat element.
mkirsch
Nomad II
Aug 12, 2020
I think you're barking up the wrong tree. Your AC should run until it reaches the preset temperature as determined by the thermostat knob, then cycle on and off as the temperature rises and falls.

It should not be running that long, freezing you out, then freezing up. Initial run in a hot camper may be a little longer but once cooled down it should not run more than half an hour at a time unless it is severely hot and can't keep up. Since it is freezing you out, it obviously is not severely hot, and has no issues keeping up.

The most obvious cause is your thermostat is not working. However, is it possible that you simply are not familiar with how an old analog AC unit works? As you turn the thermostat knob, the wider the line, the colder the setting.

When I set my AC, I simply turn it to max cold, let it run until the camper gets to the desired temperature, and then turn the knob back until the compressor shuts off. Then it will cycle on and off to maintain that temperature.
toddb
Explorer
Aug 12, 2020
If it ices over before it reaches the set point of the thermostat it's most likely low on refrigerant.
JrStafford
Explorer
Aug 12, 2020
mkirsch wrote:
I think you're barking up the wrong tree. Your AC should run until it reaches the preset temperature as determined by the thermostat knob, then cycle on and off as the temperature rises and falls.

It should not be running that long, freezing you out, then freezing up. Initial run in a hot camper may be a little longer but once cooled down it should not run more than half an hour at a time unless it is severely hot and can't keep up. Since it is freezing you out, it obviously is not severely hot, and has no issues keeping up.

The most obvious cause is your thermostat is not working. However, is it possible that you simply are not familiar with how an old analog AC unit works? As you turn the thermostat knob, the wider the line, the colder the setting.

When I set my AC, I simply turn it to max cold, let it run until the camper gets to the desired temperature, and then turn the knob back until the compressor shuts off. Then it will cycle on and off to maintain that temperature.

Hmmmmm.....There's not a thermostat, just the knob that adjusts cooler and warmer, maybe I need to adjust it down? I know it works, if you set it lower, the AC cycles on and off. It's definitely been hot here, I went into the camper yesterday in the middle of the day and the inside temp was 104 lol. Running the AC on high for 30 minutes cooled it right down, but it just keeps getting colder and colder until the temp in the camper is about 63. I will try the knob to see if it helps to stop the freezing up by cycling on and off.
JrStafford
Explorer
Aug 12, 2020
toddb wrote:
If it ices over before it reaches the set point of the thermostat it's most likely low on refrigerant.

No thermostat, and it will make the camper COLD. It can be 95 outside, and the AC on high will get it down around 60 if you run it long enough. I'm going to try and adjust the Colder/Warmer knob on the AC to have it cycle to just outside air after it gets cold.
AnEv942
Nomad
Aug 13, 2020
Yes that's the purpose of the 'knob', in lieu of a thermostat, controls temp by cycling compressor to maintain. It also isn't drawing outside air but pulling air from inside.
The cut wires- not sure but they maybe 12v hot/ground for a standard vent. Unless you meter I'd cap in case hot.
Joe417
Explorer
Aug 13, 2020
I think the aluminum "wire" in your picture just to the right of the connector is your thermostat.

It monitors the temp of the air coming back into the AC and turns the compressor off when the temp reaches the setting of the knob.

If you turn the "colder/warmer" knob down (that is the thermostat) to minimum and the unit does not shut off after it cools the TC, then the thermostat is bad.

The unit can freeze up if the humidity is high and it isn't cutting off.
JrStafford
Explorer
Aug 13, 2020
Joe417 wrote:
I think the aluminum "wire" in your picture just to the right of the connector is your thermostat.

It monitors the temp of the air coming back into the AC and turns the compressor off when the temp reaches the setting of the knob.

If you turn the "colder/warmer" knob down (that is the thermostat) to minimum and the unit does not shut off after it cools the TC, then the thermostat is bad.

The unit can freeze up if the humidity is high and it isn't cutting off.

You are absolutely correct on that one. That wire has a little ball at the end that is clipped right in the air intake. It's definitely working, I can change the 'colder' knob, and you can feel it click and cut the AC to just air. I'll experiment tomorrow, hoping that if I don't have the cold as far as it will go on 'colder', the AC will cycle on and off as it should. I've just always ran a camper AC as cold as it will go, all the time. Maybe I can't do that with this one? I don't think I've ever seen a camper AC run as cold as this one.

If it's still showing ice on the lines and compressor, then the one poster above is probably correct....It's low on refrigerant and probably will take a dump on me.
specta
Explorer
Aug 13, 2020
With mine set on max cold it will freeze me out of my camper and the compressor never cycles.

Even on 100 degree days I have to turn the temperature control knob to about the middle between blue and red.

I've never let it run until it freezes up. I'd freeze to death long before that.
mkirsch
Nomad II
Aug 13, 2020
JrStafford wrote:
It's definitely working, I can change the 'colder' knob, and you can feel it click and cut the AC to just air. I'll experiment tomorrow, hoping that if I don't have the cold as far as it will go on 'colder', the AC will cycle on and off as it should. I've just always ran a camper AC as cold as it will go, all the time. Maybe I can't do that with this one? I don't think I've ever seen a camper AC run as cold as this one.

If it's still showing ice on the lines and compressor, then the one poster above is probably correct....It's low on refrigerant and probably will take a dump on me.

If the AC can NOT keep the camper at the desired temperature without running all the time, there is something wrong. The temperature outside is too extremely hot, the AC unit is undersized, or the AC unit is faulty.

The way your current AC is working is how it's SUPPOSED to work. You're supposed to be able to set the temperature and have the AC unit cycle on and off.

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