thanks guys, finally got to read a short training manual on this drive unit. did a quick read, looks like i will have alot of studying to do. i do have a few questions though. the machine i have is a mx20, it says in the manual that the resolver is built into the machine with no bearings or anything mechanical to wear out. Is this something that fails frequently?, if so, is it easily replaced? another question is, does the resolver also function as the position encoder for the system? I have not read anything about the function of the governor tach as aqua dog indicated. is this more of a safety monitoring device, or does it also work its way into the drive feedback system? another stupid question, while i was inspecting the car, i noticed when i stopped, the machine would move what seems to be a few inches side to side. is this normal? also, vatorman, i read the part in the manual about the audible beeps, that may help you find a problem, i will pay more attention next visit, I am really starting to feel sorry for the young guys, this unit seems to be quite sophisticated, i will have to spend quite a bit of time, studying in order to comprehend all that is going on here. Oh how i long for the days of the 6850 selector. Ha Ha