I have an E-15 that I restored several years ago. Over the past
        year or two, the speed controller has been getting increasingly
        wonky. When going forward, it sometimes will not go past the
        lowest speed setting. Especially if I turn the mower blades on
        first, and then try to start moving forwards. It's more likely
        to obey my command to go faster if I first move the speed
        controller to a higher speed setting, and once it's going at
        that speed, then turn on the mower blades. Of course, that's
        rather inconvenient.
      
      
      
      Last weekend, I couldn't get it to go out of first speed no
        matter what I did. I found something in the archives about
        connections 10 and 11 (if I remember correctly) on card 1 being
        related to speed control, so I cleaned those up with some
        Deoxit, and reseated the contact "plugs", and that got it to
        work somewhat. It was still misbehaving a lot, usually requiring
        me to start moving before turning on the mower blades, but at
        least I could get it to go past first speed.
      
      
      
      Anyone have an idea what the problem is? 
      
      
      
      In general, I try to drive around in 3rd speed while mowing -
        so bypassing the big resistive bands, but not using any field
        weakening. I *think* that the system may often bypass speeds 2
        and 3, but allow me to do the field weakening. Is the resistor
        bypass controlled independently of the field weakening? (I know
        the speed selector on the dash lets us choose speed, what I'm
        wondering is if the field weakening circuit is independent of
        the resistor bypass, such that the latter may work while the
        former does not. I suspect that would be the case)
      
       
      
      Hmmm... I should drive around in a higher speed for a while,
        and see if the resistive bands are hot.
      
      
      
      Thanks!
      
      Mike
      
      
      
      
        
          
            
          
          Michael S. Briggs, PhD
          UNH Physics Department
          (603) 862-2828
          
            
          
         
       
      
      
      
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