How can i fix my Hotpoint FF92P Fridge Freezer?

I have a problem with the fridge section on my Hotpoint FF92P, the temperature keeps creeping up to 16degrees. I have linked out the fan(so it runs continiously) in the freezer which feeds the fridge to prove that the compressor brings the temp down. As soon as i remove the link and let the temperature be controlled it creeps up to 16 degrees. Is the issue faulty thermistors or somewhere else??

Thanks in advance