Help alder Barbour fridge won’t turn off

[JBas]

So my alder Barbour 12v fridge wont turn off. The compressor just keeps running. The fan wire also came loose when the fan was re connected the compressor would run but it wouldn’t cool the fridge down.

I replaced the thermostat as the old one wouldn’t even turn the fridge off manually. The new thermostat will turn off the unit Off manually but it won’t switch it off once the fridge is cool enough even on the lowest setting.

I also removed the negative wire from the module and the compressor turned off.
That’s all the trouble shooting I’ve done this far. There was a refrigerant leak two years ago but it was fixed at the time but perhaps another leak developed since.

If a refrigerant leak is the issue I have gauges and gas any idea what the levels should be at? it’s a small fridge and a 4amp system approx 6 years old.