I have done battle several times with this issue All three times it has been the Heat/AC control head . This time apperantly the fan motor did burn up : but it did not blow the AC fuse instead it fried the circriutry on the printed circuit board!! Some it is just the fan temp sensor. Some times it can be the fan motor. The fan relay under the L/H headlight does go out: but seems to be the most dependable part of the system!! I have gone to school so to speak on the 86 that Charley now owns My own car most recently: and a 88GT some time back. The first sign that the problem is your control head is when all other options have failed. Then you hot wire the fan motor close the hood and get on the Tech Line. Hope some of this will help someone out.Always feel free to call me if I can be of help!! Aerodon.
