Ibiza Sytem Porche 92 heating 92

I am reforming a Seat Ibiza of 92. It has heating and air conditioning.
The heating does not work for me and I go to Seat and in its workshop manuals it does not come out that it has heating and I am sure that it has the first month that I had it worked.
Could someone help me ???
I found a double with a coil, under the radio, and it was black took it to the SEAT and they lost it to me. Can that be the problem ???? It is 1.5 90cv five doors.