Why don't my windshield wipers work on high speed?

I have a 92 Honda Civic Si and i'm having a problem with my front wipers, sometimes they work, sometimes they get stuck and sometimes they don't work at all. They only move when i turn the off button. I changed the motor and its doing the same thing. Could it be the linkage?

Bad switch.

Do this. 2014 minus 1992. I did. The number is 22 or possibly 23 depending when the Honda Civi SI was assembled and brought into life. There are averages as to miles per year, 12,000. That means over 250,000 miles. But there's no number given for the activation of the start switch, brake pedal, turns or windshield wiper switch activations, etc. Just like "don't" and "i'm" are incorrect English grammar that you elected to use, you went ahead and purchased a new motor when this was a guess. IF the motor was bad, would the wipers have worked at all? What tells the wipers to operate at low or at high speed? Not the motor. So, having wasted time, money and effort in this guessing action, and having failed, you turn to non professionals, us, for more guesses? That is the way you wish to play this game? Just like the grammar errors, the mechanical repair errors shall continue unless you decide to take proper action. Since you are not a mechanic and we're not mechanics either, all we can do is to seek the professionals that would know, have the experience and can tell you what is wrong and how much to repair the item on this 23 year old Honda Civic that is a testimony to the qualify of product that the Honda Corporation achieves year after year. The vehicle in the photo is a 1910 Rolls-Royce Silver Phantom. It is quite old and from the start of the automotive industry development. It is in excellent running condition, all items repaired as needed and since this car is a collector's item, very valuable. I use this an example that cars can last for a long time, no one really knows how long, with proper care and repairs. This car is doing well by any standards. Please, meet Honda halfway and procure proper repairs. No guessing is allowed when repairing cars. It is way more expensive.Why dont my windshield wipers work on high speed

It could be the switch, or maybe a relay, or possibly the wiring. I was going to say the motor brushes, but you say you changed the motor unit. Mine works ONLY on high speed. The other speeds are intermittent. I think my problem is the brushes. There's a common brush, a low speed brush, and a high speed brush. Thats how they get two speeds from a single speed motor.