Has anyone had problems with their Waeco fridge's poly fuse?

I have a CF50 which runs perfectly off 220v and off 12v when the engine is running. When using either starter or deep cycle aux battery, the compressor starts and runs for less than one minute before the red error light starts flashing. I have also tried the fridge directly connected to batteries in two other vehicles. The same problem.

The dual battery system in my Pajero was installed by Safari Centre using National Luna gear, thick cable and Hella connectors. The aux voltage at the back with the fridge connnected and the engine off, ranges from 12.4v to 11.9v after 4 hours. The starter battery voltage is also around 12.5v rising to 14.6v when the motor is running. The battery protection setting on the fridge is set to LO which means it should be happy with 11.1v.

The fridge has been to the agents twice, but the probelm still exists. Google informs me that there are many instances similar to mine on the Australian 4x4 sites where the polyfuse was the problem. Apparently there was a faulty batch a while ago. Replacing the fuse sorts the issue out. I asked the agents to check and replace the fuse the last time. From the job card it does not appear as if it was done.

Does anyone have the same problem where the compressor runs for a few seconds and the red error light then comes on?