The electronic unit is a dual voltage device. This means that the same unit can be used in both 12V and 24V power supply systems. Maximum voltage is 17V for a 12V system and 31.5V for a 24V power supply system. Maximum ambient temperature is 55°C. The electronic unit has a built-in thermal protection which is actuated and stops compressor operation if the electronic unit temperature gets too high.

Before ordering, test your compressor windings. 
The controller is mounted on the compressor and is secured by a screw. Removing the screw allows the controller to be levered back to expose three wires that connect to the compressor via a three-way plug that is a friction-fit onto three pins on the compressor. The reading between any two of the three pins should all be the same; approximately 1.5-3 ohms. There should be no continuity between any of the pins and the compressor shell.

Troubleshooting
If you are having issues with any Danfoss based DC refrigeration system, these Troubleshooting Videos from Penguin Refrigeration in the UK are a great resource.

SPECIAL CONDITION OF SALE
A faulty compressor may cause damage to this controller. As this is a replacement part and operation depends on the condition of a used compressor, we can not offer any form of warranty or replacement.  Do not purchase unless you are prepared to accept this condition of sale. Outback Marine will not accept returns.