If you have a intermittent wiper set up on your AMC and you did a plug and play. Then you hook it up and you get only one speed, and no intermittent wiper motor access. Many on here have thought, bad ground, then if that didn't work, it must be a bad intermittent box or wiper switch. Well we have all been overlooking a bigger thing. You MUST have the black intermittent box bolted to a steel frame. Remember the switch is to be grounded, but not enough. The Black Box needs a ground as well. I just about had given up and was going to throw the black box. So I drilled two holes to bolt on the black box to the metal frame in the dash...tightened it up, and everything works. Remember the black box needs to be bolted down for a ground too. Don't throw it behind the dash. It needs to be grounded as well as the switch wiper. Mine works like brand new. Before, I only had one high speed. I figured this out be looking in the scrap yard and looking at 4 black boxes from Matadors, Ambassadors, Eagles, Kammbacks. It was an amazement. Try it. You won't be disappointed. Jayson