"The outside 2 were for the sanders and both had to be hooked up as the one side did the front sanders and the other side did the rear sanders."
Interesting. I didn't know they were controlled separately. Makes sense, I just never thought about it. I looked it up in the GP38 manual. According to that, the basic control switch is non-directional, just on or off. Which sanders operate is determined automatically by the reverser setting. A directional switch can be supplied if desired. That's why I never thought about it - my father didn't run diesels much, and when talking about his steam days, he never mentioned anything beyond "using sand".
Learn something new every day!
