Troubleshooting Adler Barbour & Waeco Refrigeration

Refrigeration unit will not Start and no LED blinks

1. Make sure you are getting the proper voltage at the input of the unit, Not at the Batteries. Be sure that your connections are good, free of corrosion, and are not lose or have fallen out.

2. Check to see if you are getting voltage through the front PC Board to the top two terminals on your Danfoss module (Skip this step if your unit does not have the front PC Board).  If not check all the fuses on your front PC Board. The 15a is the main fuse for everything, and the five amp is for the fan and pump circuit. There should be another 0.50-amp fuse on the back side of that PC board, that is in line with the thermostat circuit. Older units did not have this.

3. If you are getting the same voltage through the PC Board to the module, the next thing to do is to bypass the thermostat circuit. To do this, you will need to remove two wires from your Danfoss module, T and C. It will be a brown and black wire. Once these two wires are removed, you will need to make a jumper wire. Put the jumper wire on terminals T and C to bridge the two, there is no voltage present to hurt anything. If the unit still does not start or try to start, then you will need to replace the Danfoss module. If so, proceed to next step.

4. If the compressor does start, then it may be the phone cord end on the thermostat, the phone cord connection on the board, or the speed resistor on the inside of the actual thermostat housing. To test the speed resistor, unplug it and ohm out across the pins on it. There are three different ones we use, and it should read across either 270, 680, or 1500. These are there to make the compressor run at the proper speed for whatever plate you have.

5. If that checks okay, there is really no way to test the phone cord connections without fancy equipment. Save yourself time and money and just bypass it. Cut the phone cord off the end of the wire coming from the thermostat, install some female push on, and plug them onto terminals C and T. The thermostat will work the exact same as it did before.

Now let’s go over the different series of blinks you may get if an electronic problem arises. The module has built in troubleshooting capabilities, that you can use a 10ma LED bulb to determine what the module thinks is wrong. The light will blink a series of times, and pause, then continue. This makes these units amazingly simple to troubleshoot. On the newer units, we incorporated this into the front PC board. If your unit does not have the LED, you can install one into the module. One end of the LED goes to terminal “D” on the module, and the other will need to be piggy backed onto the positive fan terminal on the module.

One blink – Low Voltage

1. Almost 100% of the time when you get one blink it is Low Voltage.

2. You will need to track down the boats wiring, find your loose connection or corrosion that is causing the high resistance. You may even have a weak cell in the battery. If you are getting this code, then most likely your unit is trying to start, there will be a slight shutter, then it will stop, and continue to do this.

3. Watch the voltage at the input of the unit. You will see a significant drop in voltage. The low voltage cut off is 10.4VDC, but you will probably never see it get this low on your meter because of buffers installed in the meter. If you see a drop of over 0.5VDC you have a problem. 

4. If you feel the voltage is sufficient, then the only other problem may be the Danfoss module. I have heard if the unit gets low voltage for a while, the module will fail.

Two blinks – Fan overcurrent Protection Cut Out

1. The module has a feature that if the fan draws more than 1 amp on older modules, and 0.5 amps on newer modules it will cut everything out. This is simple to troubleshoot.

2. Disconnect the fan terminal from the PC Board on newer model or from terminal F on the Danfoss module. If the unit still blinks, replace the module. If not replace the fan.

Three blinks – Motor Start Error

1. If the compressor cannot achieve a certain RPM in a given time, the module will kick it out.

2. Three things will cause this: pressures have not equalized yet, unit has been overcharged, or the Danfoss module is defective.

3. One, leave the unit off for fifteen minutes, if it starts, then your unit had short cycled for some reason. No need to worry unless it does it all the time.

4. Two, unit was charged recently, and has been overcharged. If the unit is overcharged, the compressor will not be able to get up to speed because it has been overloaded. Get somebody on board who is EPA Certified, to recover the refrigerant, according to the law and EPA standards.

5. If none of this is the case, then replace the Danfoss module, please remember, there is no way to determine whether it is the module or the compressor, other than replacing. However, with all the Danfoss compressors I have really heard of only a couple failures.

Four Blinks - You have a Major Issue

1. Four blinks you will have to replace the module. This is usually never seen.

Five blinks - Lack of Ventilation

1. 5 blinks mean lack of ventilation. If the unit runs for a while then flashes this, then it is a lack of ventilation. Units need at least 100 sq inches of air space to operate correctly. Remember the more air it can get the better it will run. It also will not work above 115 degrees without the water-cooled option.

Everything runs, but my unit is not cooling, or there is minimal cooling

1. First, check your condenser coil (radiator beside the compressor), and make sure that it is clean and free of any kind of debris.

2. If all that checks okay, call a technician. There is most likely a leak in the system. The leak needs to be found, fixed, and recharged. You must have an EPA Certified person to do this.

Danfoss Compressors

Waeco and Adler Barbour have always used Danfoss compressors; however, they have changed over the years. There are two different types of compressors, 3 pin and 4 pins, with 3 being the newest, and 4 the oldest. You will need to remove the module to see how many pins your compressor has. There really is no way to bypass the module, to hard start the compressor. However, you can ohm the compressor pins out, to see if you may have an open or shorted winding.

Your unit will draw when running anywhere from 4 to 6 amps. That depends on how much you have in the fridge, how hot it is that day, ventilation, clean coils, insulation, etc. If your unit starts drawing higher amperage, it could be a few different things going wrong.

First, check the voltage at the input of the unit.  The lower the voltage gets, the higher the amp draw.

Second, check your condenser coil to be sure it is clean. If it is dirty, and has poor airflow, it cannot condense and disperse the heat like it is designed to do.

Another is the unit has recently been overcharged. Get a Refrigeration Technician to look it over. It may indicate your compressor is going bad, but it is exceedingly rare to see these things fail.

Unit blows fuses constantly

If your unit is blowing fuses as soon as it tries to start, it is usually the compressor or the Danfoss module. Disconnect the module plug from the compressor, leaving everything else wired like normal and try to restart. If it does not blow the fuse, then the compressor is bad. If the fuse blows then the module is bad.

If your unit is older, and does not have the PC Board

Basically, everything is still the same; you just do not have the convenience of having the LED already there. Will not start, bypass thermostat like above. Trying to start, monitor voltage, unplug fan, then replace module. Follow the same steps as above to find out what is going on.

Remember you can add that LED, you can install one into the module. One end of the LED goes to terminal “D” on the module, and the other will need to be piggy backed onto the positive fan terminal on the module.