Waceo CF50 problem

I had a random similar issue with a no-name Chinese fridge modified with a Danfoss BD-35 compressor, which I believe is what is in the Waeco. (The suspension in the original Chinese copy of the Danfoss, a Domus, failed, hence the upgrade.)

The problem turned out, after trial and error, to simply be a bad connection in the ribbon cable between the display circuit board and the main controller board (not the internal Danfoss one). Removing the ribbon, cleaning the connectors and re-installing fixed it.

Your problem may be something as simple as that.

If you're handy with tools it may be worthwhile carefully poking around a bit, checking for loose and dirty connections.

Paul
Not sure if same fault, but I repaired one which had the NTC thermistor faulty. Some seem to fail and give wrong resistance reading to the comparator circuit on the board.
If you can open the circuit part and unplug the two wire cable going down into the insulation, it should measure around 10,000ohms when at 20C ambient, if not it may be faulty. Because they carry a minute current to detect the resistance, moisture and applied temp cause the junction of the NTC chip to not work well. I purchased a 10,000 ohm NTC resistor and soldered two wires to it which were then connected to same circuit contacts. The fridge then worked as required.
Using a very powerful LED light source shining into the base you can see where the sensing end is under the plastic liner at the bottom. Usually midway other end to compressor. Knowing that, I cut a ciggy packet sized square out of the case base to access the faulty sensor. On the wire, I cut off the old sensor and after attaching the new one with wires now attached, all was securely sealed and glued to underside of plastic liner. Fridge now has worked properly for two years. The void I carved in the case was filled with expanding foam and the cut out case bit simply soldering iron welded/plastic welded to repair that cut out. There are a few faults happen with them, this is only one of those. Hope you find it.

Not long ago my CDF11 started to get temp changes usually have it set around 2 or 3 deg it went into the minus region around -5, -7 deg etc rang the local repairer he was pretty honest said it would cost a bit just to diagnose the issue so recommended replacing the thermistor found one for $30 swapped it out it works fine now you can get them cheaper. It may be your issue not sure.

What I have found, first off suspect a power problem to the fridge, ie faulty lead or plug etc.

If power ok then most problems seem to be caused by either the temperature sensor as written above, or the voltage regulator.

In my particular unit though it turned out to be the processor PCB, on initial turn on compressor would run for some time and cool down the fridge, then cycle on and off rapidly, temperature control had little affect,
turning it down would result in compressor running for a short time then going back to rapid cycling.

If you do need to change the thermistor, you don't need to cut the plastic body of the fridge or remove the old one at all. Just leave the old one where it is and install a new one up against one of the condensor coils from the compressor end. If you ring Waeco in QLD and give them your fridge model they will give you the exact measurements where to dig out the foam and where to install the new thermistor with thermocouple paste (from Jaycar). You then back fill the hole you dug out with expanding foam and remove the two wires from the RS thermistor where they connect to the PCB and plug in the two wires from the new thermistor.
In my experience when the thermistor fails the digital read out indicates a higher temp than the actual fridge temperature and the big indicator is that the compressor just keeps running 24/7 even though the fridge is cold because the digital read out is telling it that it isn't cold.

Thanks everyone

Should the fridge show the same problems if I plug into 240v. I have just got access to mains power (we travel full time) so I will see how it goes.

Cant say I'm all that confident doing what you have suggested but will look into it

Paul