Insert the end of the wire thru the defrost tray hole (RA) first then push most of the wire thru the defrost hose (YA) going out the back to the outside. It helps to have someone on the outside shaking the defrost hose to get the wire to push thru. Some variations on defrost hose sizes. Some Dometics will have a defrost cup under the tray, so the wire does not go thru tray in this setting, but only gets pushed out thru the cup attached to the defrost hose. (BA)
