can someone please tell me what defrost timer i need for a true freezer model t-23f , serial 1315509. true sent me a ge grasslin dtsx-im-120 . this thing is totally different . i called true and talked to a service man and he said thats the one it calls for . he said it would work with a little wiring . im taking it back to my supplier tomorrow but i need a part number to give him . the one i need is a paragon something. any help would be appreciated .