Make sure you buy a quality motor and quality wiper arm + blade. The original motor, arm, and blade on my boat were very poor quality and lasted only a few years. I went to Englund Marine and asked to make sure the replacement I bought was a quality motor, arm, and blade. One of my crew and I installed it and a new switch, way better. It's a two speed motor and returns to the starting location automatically instead of me having to time when I turned it off. Unfortunately I didn't buy one with an intermittent setting, sure wish I had. An adjustable intermittent setting would be even better. The replacement has been working great for quite a few years now and I expect it will keep working for a while longer, hopefully quite a while longer. It seemed expensive at the time, but was definitely worth it. I thought so the first time I used it and continue to think it was worth it.
ron m