whirlpool american style f/f

Hi I posted a query on this a little while back no feed back unfortunately.Anyway I got the customer to order a new air diffuser (from yourselves)which I installed it did have a different connector block to the original 1 side 2 connectors the other side 3 connectors I used the 3 way as that was the same as the original & it duly closed as i was fitting it,all went well with the temp in the fridge for 4 days but now it refuses to open.Is it poss to put this m/c in a self diagnostic mode like the whirlpool/kenwood models to see if it’s the diffuser,thermistor or board fault.The model no is FRSS2VAF20/0.Hope one of you lads can help.Mack.