Visit our Popular Forums

Ray Eklund · 06-06-2014, 07:10 PM

Safari 23 foot, 2006, factory mounted A/C Duo-Therm Penquin, Serial Number 54442608, #620315-325-415-425.62 on ID Plate.

I used this unit on its 2006 maiden trip to Las Vegas, Nevada. Full Hookups at Sam's Town Casino RV Park. Worked great in the 100+F days.

I used this unit on this June 2014 trip to Las Vegas, Nevada. Full Hookups at Sam's Town Casino RV Park. Quit working on the 4th of 7 days in 98 to 110F days. Considering I dry camp with NO ELECTRICITY... this A/C could be described as barely used. It has been used for about two weeks of Las Vegas... "camping". This second trip to Las Vegas it bites the dust, as we say when camping off the beaten path.

Symptons:

(1) The day the unit quit cooling, when the compressor quit it made a "thump" sound. Not a quiet end to the cycle... but thump, thud... something of that nature. That is the only thing I recall before it quit cooling. It was working when it would stop and makes its transition from cooling to resting. It may be the sound that ALL the Dometic A/C units make when the compressor stops.

(2) The FAN works fine. With A/C or just for fresh air circulation.

(3) The system was set 15F to 20F degrees BELOW the current temperature. So if it was 100F... set it at 80 to 85F depending on the comfort level. It would cool down and then cycle when maintaining a temperature. After several days of 110F or... less... you do get comfortable at 90F. Parked under some shade from the palms or trees it was quite comfortable. The A/C added considerably to the comfort level without overdoing it.

(4) When the A/C quit cooling there was a SMELL / SCENT of hot electrical wire or, maybe a starting capacitor? The compressor quit, tried to start and would cool for a second and quit. Since hot electrical "smell" is a Red Flag for me... I shut the system down and inspected the unit by removing the filters. I find that the "goods" are on top and you have to gain access from the top cover... OK, I need a ladder for this look. Using the air blower and opening trailer windows did make it tolerable for sleeping and day time comfort. While running on Fan only... no problem at all at any speed.

(5) Has anyone experienced these symptoms and found the faulty part or parts? My biggest clue has to be the electrical hot wire smell. I have not removed the top cover to examine any parts, as we arrived home from several days camped near Medicine Bow, Wyoming where you need HEAT, if you need anything. But, wanted to get to this NEW problem, after curing the Dometic Refrigerator problem solved BEFORE this trip to Las Vegas.

I noticed lewster of Oregon hit one problem perfectly, so am hoping this is noticed by anyone with previous A/C symptoms as mine.

tcrum · 06-06-2014, 08:04 PM

Just got my third dometic installed today. Since september 2012.

Pileus · 06-06-2014, 08:36 PM

Do you monitor AC voltage in those campgrounds on hot days?
I had a unit burn up due to low voltage on a previous RV (SOB). A good meter is a must.

Silver Goose · 06-06-2014, 09:40 PM

I had a similar incident a few years ago. I know the compressor wouldn't start and the burnt electrical smell was potent. I don't recall if I tried running the fan by itself. The fix in my case was about $35 in parts and my time.

With electrical and ladder safety first, get on the roof and remove the plastic shroud. Then look for a metal cover over the electronics and remove it. Mine was on the curb side. You should see the start and run capacitors and on mine, attached to the top of the start cap was a small component known as a PTCR, or what was left of it. The half that remained was very charred and smelled exactly like what I smelled at the failure. A local RV parts store stocked the one that fit my model Penguin (that in itself may say something about the reliability of this component). The cap looked okay but I replaced it along with the PTCR as was recommended to me. A few minutes back topside exchanging the parts taking care of what was connected to what and the Penguin was back to doing its job.

Gnorts · 06-06-2014, 10:22 PM

Meet The Positive Temperature Coefficient Resistor

Meet The Positive Temperature Coefficient Resistor

lewster · 06-06-2014, 11:16 PM

Ray,

Silver Goose has the answer. The electrical burning smell gave it away. Your PTCR (motor starter) and start capacitor should be changed out. Any local RV tech should be able to handle the job, or you can do it yourself with OEM parts from Dometic.

Quote:

Originally Posted by Ray Eklund

Safari 23 foot, 2006, factory mounted A/C Duo-Therm Penquin, Serial Number 54442608, #620315-325-415-425.62 on ID Plate.

I used this unit on its 2006 maiden trip to Las Vegas, Nevada. Full Hookups at Sam's Town Casino RV Park. Worked great in the 100+F days.

I used this unit on this June 2014 trip to Las Vegas, Nevada. Full Hookups at Sam's Town Casino RV Park. Quit working on the 4th of 7 days in 98 to 110F days. Considering I dry camp with NO ELECTRICITY... this A/C could be described as barely used. It has been used for about two weeks of Las Vegas... "camping". This second trip to Las Vegas it bites the dust, as we say when camping off the beaten path.

Symptons:

(1) The day the unit quit cooling, when the compressor quit it made a "thump" sound. Not a quiet end to the cycle... but thump, thud... something of that nature. That is the only thing I recall before it quit cooling. It was working when it would stop and makes its transition from cooling to resting. It may be the sound that ALL the Dometic A/C units make when the compressor stops.

(2) The FAN works fine. With A/C or just for fresh air circulation.

(3) The system was set 15F to 20F degrees BELOW the current temperature. So if it was 100F... set it at 80 to 85F depending on the comfort level. It would cool down and then cycle when maintaining a temperature. After several days of 110F or... less... you do get comfortable at 90F. Parked under some shade from the palms or trees it was quite comfortable. The A/C added considerably to the comfort level without overdoing it.

(4) When the A/C quit cooling there was a SMELL / SCENT of hot electrical wire or, maybe a starting capacitor? The compressor quit, tried to start and would cool for a second and quit. Since hot electrical "smell" is a Red Flag for me... I shut the system down and inspected the unit by removing the filters. I find that the "goods" are on top and you have to gain access from the top cover... OK, I need a ladder for this look. Using the air blower and opening trailer windows did make it tolerable for sleeping and day time comfort. While running on Fan only... no problem at all at any speed.

(5) Has anyone experienced these symptoms and found the faulty part or parts? My biggest clue has to be the electrical hot wire smell. I have not removed the top cover to examine any parts, as we arrived home from several days camped near Medicine Bow, Wyoming where you need HEAT, if you need anything. But, wanted to get to this NEW problem, after curing the Dometic Refrigerator problem solved BEFORE this trip to Las Vegas.

I noticed lewster of Oregon hit one problem perfectly, so am hoping this is noticed by anyone with previous A/C symptoms as mine.

Ray Eklund · 06-07-2014, 10:37 AM

Thank you so much for your welcomed comments!

Next week I will be on top of my Airstream and see what I have to work with. When in Las Vegas there was a number of Air Conditioning failures. Many on the Bus and RV's units. At least some of these had TWO Air Conditioning units- one near the front and the other near the back.

There was a RV Service business just a mile north of Sam's Town on the west side of Boulder Highway. Easy to get to and I drove there, Saturday, and saw at least ten, probably more RV's needing work of various problems. They were pretty well booked for the following Monday and did service checks for $150 on diagnosing A/C problems. Weekends were off days for service. We would have to be on a wait at the lot to be squeezed into the full schedule. Since we were planning to leave Las Vegas on that Monday... we headed to high country and did not need any A/C in Nevada and then to Wyoming... which had highs in the mid 70's and lows in the 40's. After getting use to 90's and 100's in Las Vegas... even 75 degrees seemed... cold.

Now that I have my story and events up to this point, we Airstream Owners do help one another. Sometimes repairs build a strong bond between owners who have to be handy to keep on the road!

One last addition and I will post my progress with this "on the roof" workout as any progress can be made.

When I looked for the Dometic Air Conditioning manual in my Airstream zipped carrying bag I found one sheet mentioning the Three Year Limited Warranty... but no service manual. The sheet listed everything I cannot do during the warranty period. No service manual. Obviously to save a few cents of overhead expenses... I learned that if I do not have a local Service Center... I can ship and have the repaired unit at my cost, or take it to the local Service Center. So, after digesting this one sheet of restrictions, I have no Warranty nor Service Manual. I am on my own and now am gaining a new Airstream experience.

The Dometic Refrigerator took some effort, but was a successful tweak to the factory mounted equipment. Taking a solder iron to some A/C capacitors will be just one more treasured memory, when something is NOT NEEDED it would work to perfection. When NEEDED and put to its limit... it fails. Now I understand when traveling on the Oregon Trail, grandma's pump organ would be tossed over the side because the oxen could not handle the excess weight of the wagon load. I feel like a Frontier Pioneer making the best out of what generous advice I can find from others who have traveled this same path. Maybe not tossing grandma's pump organ onto the prairie, but I will do it symbolically and imagine what I might have done to this unit. Seeing on some trailers at the RV Park with a self installed, more reliable WINDOW A/C apartment sized unit, some 2x4 lumber and pressed up against the trailer's siding into a side window for consistent cool air, it gives me another option.

lewster · 06-07-2014, 11:44 AM

Ray,

You won't need a soldering iron to change capacitors as they all have 1/4" spade connectors. If it is your PTCR and/or start capacitor, a simple visual/smell test (you apparently have already experienced the smell part) to see if they have burnt out.

You simply need the correct replacement parts to do the repair. It will take far longer to access the location of the capacitors than to perform the actual repair!

Pileus · 06-08-2014, 07:39 AM

"When in Las Vegas there was a number of Air Conditioning failures. Many on the Bus and RV's units. At least some of these had TWO Air Conditioning units- one near the front and the other near the back."

"Quit working on the 4th of 7 days in 98 to 110F days."

I would suspect heavy demand on the Park's electrical service may have put you in a near brown-out situation. To avoid future problems, knowing when this condition occurs is essential.

Ray Eklund · 06-11-2014, 03:00 PM

Finding a technique to get onto the roof of your Airstream is your option. Make sure once you are on top that you step only on the riveted frame supports and not on the aluminum skin without the support.

Go to your electrical box and switch the 30 amp OFF for the A/C.

(1) Pulling off the plastic cover removing four philips screws is the easiest part.

(2) There is a sheet metal cover that protects the electronics. Remove.

(3) Once the cover is removed you will see a large grey capacitor. Mine was marked M24P3720W10 MRP 224880 (the last 80 is very faint so suspect) This had no hot electrical smell. It is held firm with two sheet metal screws. Remove the easy to get to screw and it becomes loose. The wiring is very tight and secured not to vibrate, so loosen gradually so you can move it out of your way to find step (4).

(4) Down at the bottom laying horizontal is a BLACK capacitor 43-52MF Lot 73222 CGE and a small black square connection call a Motor Starter WSX-7. ( It was crisp and smelled.) The black capacitor smelled. These two components had failed. I used a long straight edged screw driver to disconnect the Black Capacitor from the Motor Starter.

(5) The black capacitor can be disconnected from the square Motor Starter (less than 1 inch square) with a long handled screw driver and slowing work the capacitor and Motor Starter apart. Take a flash light if you want to see better if in a garage and indirect lighting to the work area.

(6) The Motor Starter is secured with a philips screw into the sheet metal and I will have to figure out HOW I am going to remove it. It may have to stay where it is and a replacement positioned in the area and secured.

Would I recommend someone who finds climbing a ladder difficult, moving from the ladder to the top of the Airstream and work on this electrical component, being able to squat securely on the riveted support... ONLY if you are agile. The electrical wiring into the circuit board are "tight". You will have to be patient and make some slack to remove the GREY large capacitor in order to SEE the BLACK capacitor and Motor Starter. It will take time just to work in this tight area of wiring.

I am 100% certain the Black capacitor and the Motor Starter are BAD. The Motor Starter is crisply burned. The Black capacitor obvious had been hot but contained the heat. There is NO question these are bad. Smell and toasted.

This is where I stopped after about one hour of trying to figure out WHAT and WHERE to look. Now, I might be able to do it in 30 minutes... which I would not wish onto anyone!

I have taken photographs of the work area. You need very few tools. You will need patience and some care in moving wiring without disconnecting any from the circuit board. This obviously was added to the A/C and then the wiring connected to everything and then screwed onto the sheet metal frame of the A/C. The getting to the problem is EASY. The rest will take some needle nose pliers to make connections due to the lack of "relaxed wiring" from the bundled wiring harnesses within this area. This is like 25 highways coming together at one of those Round-About traffic circle. It is TIGHT in there.

I will be ordering the black capacitor, grey capacitor and motor starter BEFORE I remove any connections. So far, only the motor starter has been removed from the black capacitor, as you cannot remove the capacitor unless it is removed.

This

Ray Eklund · 06-11-2014, 05:45 PM

The grey capacitor is marked: MRP 224880, 20+, 10uF, 370V, 50/60hz, C22, 2No 190, (FHC), M24P3720W10, 0539.

The black capacitor is marked: CGE, "A" Assembled in Mexico, 47-56MF, 250V, Lot 73222

The Motor Starter: WSX-7, Motor Starter

The A/C shows models 620315/325/415/425.62.

At PPL RV Parts for 620315321 13,500 btu unit parts Start Capacitor 3100236235, 47-56m/250v- AND Start Capacitor (black and looks like mine).

Fan/Run Capacitor VAX 50/60hz- Use 49-9556 (grey and looks like mine)

My original parts are 43-52MF and these available as 47-56MF. Is that too big of a difference?

The Motor Starter WSX-7 is a rectangle, hard material that the capacitor plugs into one of its male connections. There is no illustration with this part offered for sale and have to assume it is one that works with the capacitor and the 2006 system.

Has anyone order these three parts from Dometic or anyone and what were their numbers? I feel I am getting close, but nothing is 100% matching and appear to be a bit larger capacity, yet appear the same.

I and led to believe that MRP and CGE are manufacturers' abbreviations (?).

lewster · 06-11-2014, 10:42 PM

Ray,

I keep them in stock. PM me for additional details.

Ray Eklund · 06-13-2014, 09:43 PM

I am picking up a kit from Lewster to replace the Black Capacitor and the Starting Capacitor that have fried. The grey capacitor appears to have not been in the circuit to start the A/C compressor. I will keep as a spare.

When these capacitors arrive, I will be getting everything back together and will test run it. As I did with the Dometic Fridge, I will describe what I did, how I did it and did it work. If I am able to help, just one other person, I have learned a lot myself and can give someone else the encouragement to try to fix it themselves.

Just from a couple clues from the Dometic Fridge Forum did I get the idea to bend a thermo couple into the propane flame to fix what had been a problematic running system. Without spending a cent, the fridge now works as it should have. This unit was purchased to replace original when the ammonia gas line weld broke and was not repairable without major expense.

I hope that I can resolve the A/C break down and the obvious steep learning curve that is testing my confidence and will power to undertake these repairs while owning an Airstream.

Ray Eklund · 06-18-2014, 05:30 PM

Received the Start Capacitor and Motor Starter today, which took less than six minutes to install. My wife turned the AC on while I was on the roof to listen to the compressor "kick in". The fan ran, the AC did not start. After several attempts I climbed off the roof and will see what my options might be.

I am running the heavy 30amp+ trailer extension cord with the house three prong plug adaptor into a garage outlet, there might not be enough amperage to start the compressor. I will have to wait as I do not have access to a RV Park hookup. The replacement parts did not smoke or get hot... I have to see that as some kind of progress.

I have to thank Lewster for the prompt shipping of the two components that I immediately installed.

Although I would have hoped that the home 110v would have had enough to start the compressor... I will need to wait until I can find a way to test the system at a later date.

J. Morgan · 06-18-2014, 06:39 PM

Sorry to say, I dont think lack of power is your problem.

I take it that these units don't use a compressor relay?

lewster · 06-18-2014, 09:05 PM

Quote:

Originally Posted by J. Morgan

Sorry to say, I dont think lack of power is your problem.

I take it that these units don't use a compressor relay?

Yep! It's K-5 on the relay board.

Ray Eklund · 06-28-2014, 10:47 AM

After getting only the AC Fan operating and no compressor activity... I put everything back together and the top cover. I replaced the the motor starter and black capacitor to get to this point....

To check the fan after this... now it did not go on. The 20 amp breaker is on. The temperature is set low to activate the compressor.

I went back onto the top of the trailer, pulled off the cover and asked my wife to turn the AC on while I was on top checking the connections from the Starter Capacitor (black one) to the grey larger capacitor. You know, the jiggle test if a wire is not making contact... all I could hear was a light click on the circuit board when my wife switched to cool and then off.

Since I now have no fan, which before did run, I have neither fan nor any compressor activity.

-I have to assume the grey capacitor may need replacement.
-The black capacitor and/or motor starter need replacement.
-When the black and the fried motor starter went bad, it affected the board.
-Or... I am going to find a window AC, build a exterior stand and fit it into the rear exit window.

Anyone have a suggestion? This is not a dead end yet, but a possibility.

lewster · 06-28-2014, 11:53 AM

Ray,

I would check the capacitors and PTCR before replacing again. Do you have a meter that reads capacitance in micro farads? PM me for the technique.

You also may have a bad relay board. I can also tell you how to check that as well.

Lew Farber
RVIA/RVDA Nationally certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

Ray Eklund · 07-10-2014, 01:36 PM

The relay board is held onto the stamped bracket it is mounted, with four compressed plastic tips. I flipped the AC breaker in the trailer. Used four tools:
Flashlight to read the relay board.

1- Long narrow tip needle nose pliers and a wider tipped with longer handle. (an 8 to 10 length is easier)
2- A stiff plastic shim about 10 inches long for leveling studs.
... and patience figuring out what I needed.

Process for removing circuit board:

-I compressed the plastic tip sticking out on the board.
-Took the stiff plastic shim, about a inch wide and used it to lever the board off of the plastic tip. The top two were easy. The bottom ones you have to rotate the tip so you can find the edge you need to compress, slid the shim in and with a light twist they slid off.
-With the board loose, I was able to get the entire board where I could easily look it over. There was a yellow, furnance wire, that was capped and not used... since we only have the AC. OK, that made sense.
-The flash light, those new 500 lumen ones from Costco!, made reading the boards numbers of resistors and connections easy. There was one fuse I checked and it looked, visually, intact and I reattached it.

K5 was a black rectangle with another similar component next to it. Of course the K5 looks more difficult to remove. I have to "assume" it plugs into the board and will look at the backside to see if it is soldered or not. It looks like I can take an adjustable plier and pull it off the board. Maybe Lewster has a comment... but I DID find the part mentioned twice. If I can do it, many other "fly by their pants repair themselves" owners can also. I do not recommend this to everyone, as it is awkward keeping on riveted cross members and if you forget to cut the power or ground one of the two capacitors... you could find yourself on the ground in short order.

Now I need to figure out WHAT K5 does. I hope someone will be so generous and explain to me the removal and replacement. I will also have to get the part. Probably a second... just in case.

I did not get back to this AC project just to take a breather and start fresh. After trying this experiment, which it is... if it seems hopeless... I will be figuring out a way to mount a removable bracket to install a small apartment 110volt window AC.

Of course... as I am working, sweating, trying to look everything over... my mind flashes to Dometic and these RV units. I rented apartments above commercial real estate in Missouri and NEVER had one of those go bad. The worst was the original owners had smaller cheaper units and no one complains in a hot and high humidity climate that the AC is too LARGE.

This is a learning experience for me and hopefully, if all goes well, and it can be repaired by those of us old farts that are tight with our cash and self reliant for repairing "mechanical" things and forced to practice on circuit boards and components... A bad wheel bearing... obvious. A bad component on a circuit board... a multi purpose ohms meter comes into play. Now, where is that digital meter I bought for the trailer? That will be the next hunt.

Thank you for the advice and I am ready to continue this long distance "operation" to continue!

lewster · 07-10-2014, 06:19 PM

If you look at the K-5 relay, you will see the 120VAC hot (black) wire entering from the trailer's 120VAC power lead to the A/C unit. The other wire coming out of K-5 (black or blue, depending on the unit and year) goes to the compressor.

CAUTION!!!! DON'T TRY THIS UNLESS YOU HAVE EXPERIENCE WORKING WITH LIVE 120VAC CIRCUITS!!!If you have the unit on, thermostat set to cool with temperature lowered and power to it, jump the terminals with a 12AWG heavily insulated jumper and the compressor should kick in. If not, it is not the K-5 relay giving you the problems, and your entire relay board should be replaced.