Kenmore Heavy Duty 70 Series washing machine doesn't fill with cold water?

I recently bought this USED Kenmore Heavy Duty 70 Series washer on Craigslist that worked fine for about 6 weeks. The only problem existing at purchase was the washer didn't stop spinning when the door was opened. Then all of a sudden yesterday the washer stopped at the rinse cycle...this was when washing with warm water. When I started another load, then turned the knob to cold, the water stopped pouring into the drum. Since the washer has all cold cycles, we determined that the lack of cold water filling the drum stopped the washer from rinsing and cycling correctly. Any idea how to fix the lack of cold water problem?