1995 Chrysler New Yorker 95 New Yorker heater problem

About a month ago my car overheated. At first I thought I had a crack in the heater hose but after replacing that I found it was coming out of the overflow. I then replaced the thermostat then after no results the resevior cap which did the trick. A few days later I tried to turn the heater on but it would not blow at all. Now before it overheated the heater/ac only worked on high and made a knocking noise for about a minute then the noise would stop. I was told by a coworker that his dodge stratus did the same thing and it was the resinator. The first thing I did was check the fuses and they were all ok. I replaced the resinator and still nothing. I checked all the wires and connections. The rear defroster button light turns on but the defroster will not work. Could it be the blower motor? And would the blower motor make the rear defrosters not work? Please help, I need to get this fixed before the weather gets cold.