# Repair Or Replace Your 12 Volt Refrigeration?



## RLK (Dec 1, 2001)

The pleasure boat refrigeration industry today is following marine industry down the drain. We have seen refrigerator companies like Grunert, Crosby, Adler Barbour, WAECO acquired by Demitic. <ST1Bay</ST1 has stop production of their boat refrigeration products. Northern Lights, a manufacturer of marine generator sets has acquired Ft. Lauderdale-based Rich Beers Marine. What seems to be missing in this new market are the experienced people that provided technical after market support in the past. The technical approach to small boat refrigeration today is the same as when you buy a toaster, if it does not work after a short warranty it is expendable so they advise you to buy a new one. The most resent loss to small boat refrigeration support is the announcement from Rparts.com that they will d*iscontinue operations of Refrigeration Parts Solution Effective June 30, 2010.<O</O*
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If someone tells you to buy new 12 volt refrigeration because compressor will not run do not believe them. If your compressor runs but there is no cooling then solution is difficult and generally requires technical help. If compressor fails to run then anyone with basic technical knowledge can find and correct a failure to run of a Danfoss compressor. If your refrigeration unit is over 10 years old and has a Danfoss BD 2 or BD2.5 or BD3 compressor then it has the older discontinued electronic 4 pin module. 
Troubleshooting Danfoss compressors with 4 pin modules will consists of the following steps:
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1. All of these compressors have a 4 pin module connector and their modules contain an external fuse. If this fuse is blown there are two reasons why either power wires to module are reversed or module has an internal failure.<O</O
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2. Check to see that there is actually power at the refrigerator control module.

3. Place jumper wire across thermostat terminals on electronic module, Compressor still does not run go next step.

4. Disconnect black fan wire from electronic module, Compressor runs, replace fan. Compressor still does not run after fan ground wire is disconnected, go to next step. 

5. Run correct size and correct polarity jumper wires direct from a fully charged battery in order to bypass all boat's wiring. Volt meter readings are of no value when looking for voltage spikes. Compressor still does not run electronic module needs to be removed and tested on another unit. If there are no other units available to test your module on I will test all 12 volt Danfoss control modules free except for BD80 compressor modules. Email me for shipping address and details. [email protected]
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VARIABLE SPEED DANFOSS COMPRESSORS 
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Small 12/24 volt boat refrigeration using Danfoss compressors manufactured after 1996 will have a BD 35 or BD 50 variable speed compressor with a troubleshooting computer chip built into their control module. This circuit makes them easier to find troubled area if compressor fails to run. If your unit does not have this $2 LED install one, as it could save you a lot of money later. Without the LED on these new units troubleshooting will be the same as earlier 4 pin Danfoss BD compressors.
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If installed trouble shooting LED will only flash if electronic module sees a compressor problem. In each case problems of compressor's failures to run are identified by Counting number of flashes of LED:

No LED flashes would indicate either thermostat is open or no power to module.
One LED flash and a 4 second pause indicates a boat wiring electrical resistance problem or low batteries. Because of modules sensitive to milliseconds of a voltage ***** they cannot be detected by a voltmeter. Solution is to bypass boat's wiring till problem is located.
· Two LED flashes indicates fan over current cutout. If fan circuit on these variable speed compressors exceeds ½ amp compressor start up will be aborted. This condition can be confirmed by disconnecting Black fan wire at module if fan runs replace fan.

Three LED flashes indicate excessive torque is required to start compressor. This is commonly caused by turning compressor off and back on too quickly or too much refrigerant or poor condenser cooling. Most people jump to the conclusion that there is a mechanical rotor lock up inside compressor and this is a mistake on Danfoss BD compressors. 
Four LED flashes indicate compressor motor not reaching sustained controlling speed above 1,850 rpm quick enough. <O</O
If someone has tampered with refrigerant by connecting gauges to a system letting air in or adding too much refrigerant can cause either a Three or Four LED flashing signal. On water cooled Danfoss condenser systems three and four LED signals are common when seawater gets into refrigerant circuit.
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If you have sources for refrigeration fair priced parts and technical assistance email them to me and I will list them on my web site. I found a source for 4 pin modules at a fraction of the price currently being asked and have been advised that refrigeration parts outlets like United Refrigeration can special order the newer Danfoss modules or compressors at a fair price.
<O</O<O</O<O</O<O</O<O</O<O</O


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## stevie_391 (Jun 12, 2018)

What would be the solution for the 3 LED flashes? Could this be not enough refrigerant?


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## eherlihy (Jan 2, 2007)

There are 5 LED error codes that the Danfoss BD35 (and BD50 - I think) can show. 
The specific error code is represented by flashes of the LED:

Battery protection cut-out - voltage out of spec
Fan over-current cut-out - Fan is pulling too much current
Motor start error - Motor is blocked, or pressure in system is too high. On my unit it happens if I try to start the diesel engine while the compressor is running. To clear it, I shut the unit off for a minute, and turn it back on.
Minimum motor speed error - motor cannot maintain 1850 RPM
Thermal cut-out of electronic unit - ambient temp is too high for compressor to maintain internal set temp.

[EDIT] Note that my post echoes much of the OP.


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## stevie_391 (Jun 12, 2018)

Thanks for your reply. 
I tried shutting down, but keep having the 3 LED flashes. 
Can I reduce the pressure?


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## eherlihy (Jan 2, 2007)

The pressure should bleed off simply by shutting the refrigerator off and waiting. I understand that it is possible to get water in the system which freezes and blocks the line. You could leave it off overnight, and let the entire unit thaw out to see what happens. The other alternative is that the motor is, in fact, blocked.


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## capta (Jun 27, 2011)

eherlihy said:


> I understand that it is possible to get water in the system which freezes and blocks the line.


We had this happen quite frequently in the late 70's to late 80's boats in the Caribbean, with engine drive compressors. Our solution was to pour boiling water on the expansion valve. Did the trick nicely for a while and w/o competent techs around, it was the best we could do.


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## Rocky Mountain Breeze (Mar 30, 2015)

The compressor not starting is likely an electrical issue, either insufficient voltage to the compressor or an internal electrical problem with the compressor. If your system has a capillary tube for a metering device the pressure should equalize within 5 minutes if it is not contaminated with moisture. If it is an expansion valve system like Capta is describing the expansion valve either has to be an equalizing type or the compressor has to be capable of starting against a pressure differential. Either way, if the system has been contaminated with moisture, non-condensibles, or the compressor has electrical problems you are going to need somebody who actually understands refrigeration and controls, which is a rare find in today's world in my experience. In the past I hired about 10 people to find one who actually knew the trade, was honest, and cared about quality of work. It has stretched to about one in twenty the past 5 years or so.


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## aa3jy (Jul 23, 2006)

Our 29 year old Adler Barbour (R12 version)failed..hopefully its replacement will last as long..


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## colemj (Jul 10, 2003)

eherlihy said:


> There are 5 LED error codes that the Danfoss BD35 (and BD50 - I think) can show.
> The specific error code is represented by flashes of the LED:
> 
> Battery protection cut-out - voltage out of spec
> ...


This is what Danfoss publishes for the error codes, but I recently came across 2 different Danfoss systems giving 3 flashes, where the problem was actually the fan drawing too much current (normally 2 flashes).

Try disconnecting the fan and see if the problem goes away.

Mark


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## fdw777 (Jul 15, 2021)

Hello All.

I have a Dometic CFX3 55IM. When connected to 120V AC the unit runs just fine. When connected to 12V DC the unit runs, however there is an occasional thump sound and we get an error "WARNING 33" which accounting to Dometic is a "compressor start fail". After a few minutes the unit resets itself and runs fine, and the process repeats itself. Dometic said to replace the unit. Any ideal how I can fix the unit, BTW its less than a year old. Thanks


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## eherlihy (Jan 2, 2007)

fdw777 said:


> Hello All.
> 
> I have a Dometic CFX3 55IM. When connected to 120V AC the unit runs just fine. When connected to 12V DC the unit runs, however there is an occasional thump sound and we get an error "WARNING 33" which accounting to Dometic is a "compressor start fail". After a few minutes the unit resets itself and runs fine, and the process repeats itself. Dometic said to replace the unit. Any ideal how I can fix the unit, *BTW its less than a year old.* Thanks


Repair under warranty. Typically, Dometic will simply replace the unit.


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## Minnewaska (Feb 21, 2010)

fdw777 said:


> Dometic said to replace the unit. Any ideal how I can fix the unit, BTW its less than a year old.


Why would you want to fix it? Will they replace it under warranty? Dometic is 5yr, I believe.


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## Minnewaska (Feb 21, 2010)

BTW, I‘m interested in having one of these portable powered coolers, as a cruising backup to a fridge failure. Every one I read about seems to be less than fully reliable.


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## eherlihy (Jan 2, 2007)

Minnewaska said:


> BTW, I'm interested in having one of these portable powered coolers, as a cruising backup to a fridge failure. Every one I read about seems to be less than fully reliable.


I repaired the CF-50 that I purchased in December of 2016. This year while returning from Florida the display and, initially, the cooler ceased to function. I _*was *_able to use the refrigerator in "emergency" mode, in which it runs continuously at reduced cooling power. It was still capable of freezing everything that we put in there. We managed this by manually turning it on and off throughout the day.

There were two issues. One is that the display/control board was only supported by 3 screws, when it should have been designed for 5. This allowed the display board to flex, and prevented the ON/OFF pushbutton microswitch from working. I repaired this by placing a ¼" thick piece of foam rubber under the board to provide additional support for the ON/OFF microswitch. The other issue was that the start capacitor on the "Main Digital PCB" failed. I ordered a new PCB (with a new cap.) for <$70, installed it, and the refrigerator is working 100%. I also bought a new display PCB (also <$70) that I will keep as a backup.


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## Minnewaska (Feb 21, 2010)

eherlihy said:


> I repaired the CF-50 that I purchased in December of 2016.


Is there a more reliable brand? Engel? Swear I've heard of failures there too.


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## deniseO30 (Nov 27, 2006)

Minnewaska said:


> Is there a more reliable brand? Engel? Swear I've heard of failures there too.


 Engel and few others (norcold comes to mind) use the Sawafuji Swing Compressor, low, almost no starting torque, and they slowly come up to speed. IT is my choice of 12/24 volt compresors. 50+ years in the HVACR business.. one learns a few things...


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## fdw777 (Jul 15, 2021)

eherlihy said:


> Repair under warranty. Typically, Dometic will simply replace the unit.


They did replace the unit, and let me keep the broken one 👍


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## fdw777 (Jul 15, 2021)

Minnewaska said:


> Why would you want to fix it? Will they replace it under warranty? Dometic is 5yr, I believe.


They did replace the unit, and let me keep the broken one. 👍


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## eherlihy (Jan 2, 2007)

fdw777 said:


> They did replace the unit, and let me keep the broken one 👍


SPARES!!!


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