Thanks so much for all the write-ups; they were most helpful and led me (luckily) to the right parts decision.
I had this exact issue as described above. I tested the wax motor resistance as several others did above and received a 1300 ohms reading -- right on spec. But about 6 mos ago, this same issue had occurred and I found a slightly loose connection at the speed control board -- the first thing I checked. That got it working with no parts replacements. So naturally, I was thinking, "OK. The connection has become loose again." No luck.
So I was faced with a "which part is failing" question and after receiving the 1300 reading, I was seriously thinking about the control board. But thanks to Don's postings, I decided to replace the part that has had the most complaints (plus it was cheaper) -- the latch assembly. It worked the first time.
Frigidaire Front Load Washer Door Lock Assembly Part # 131763202