My gradall recently locked the rear wheels in reverse. We had to disengage at the hubs in order to move. According to the diagnostics in the book, it's looking like the diode is the culprit, but darned if I can find it. I've studied the electric schematic and while it shows there, there is nothing in the book that tells me what it looks like or where to find it. Any help would be greatly appreciated.
I got to pick a pros brain the other day and he told me that there are probably a bunch of diodes on my machine. He also said that they are a small clear tube with a wire at each end and generally are not within the loom, but left outside of it to allow servicing. He said that low voltage could cause it to burn out and I have been having a problem (still unresolved) with the charging system so that makes perfect sense. I'm about to dive in and will keep the forum posted for whoever wants to know.
OK, in case someone has the same problem in the future, the problem was a faulty reverse switch located under the dash. My first test of it didn't show it as bad, but after banging my head against the wall for a few hours, I went back to it and you know the rest of the story...