Air Conditioner problems of the 1999 Jeep Grand Cherokee

The blower to the heater and air conditioning went out. I have had it replaced 2 times in less than 3 years. Now its out again. It's difficult to drive in winter with no blower to a heater and difficult in summer with no blower to the air conditioning. A mechanic I went to said he has seen multiple Jeeps with this same issue. He believes it may be the cable wires due to the nearness to the engine and they were not big enough to handle the heat. Is this true? he also thought Jeep was aware of this issue. If so, how do I get this fixed so it works properly and not go out every year? every once in a "blue moon" the blower will come on for a couple seconds but will not stay on.