Okay, I have to go by a '94 WD because that's as far back as ASIST goes with Maxima SM's, but I'm pretty sure your car will have a similar setup. There's a "Time Control Unit" that handles all the electrical timed-events, beepers, interior lights, etc, and the intermittent wipers. It gets signal from a potentiometer inside the combination switch. Since you didn't mention any other "timed events" malfunctioning, my bet is on a bad pot. If you backprobe the combo switch wiring, you should find one pin where the voltage moves up and down when you twiddle the intermittent control. If so, then chances are your Time Control Unit is dead (bad news because it's a discontinued part). If there's no movement, then chances are the combo switch is bad (better, because at least you have a prayer of finding one). Hope this helps.