Got it out, (looks just like that) read the numbers on it off to the Williams rep in S.C., and was told "no such number!" After the usual voice mail, on hold, dropped calls thing, all while swing trusses, we finally figured out there were two groups of numbers on the thing, one set (that didn't compute) must be the plastic mold number or something, the parts guy was puzzled, the set I needed are stamped in the that lower rectangular section, and they are a series of dots, that comprise the number. Zoom in on that Ebay picture, see what I mean?! I showed it to several people on the storm tank run off job I was on, "here's the part, what's the number?" They all did like I did, got the easily visible number and never noticed the dots.... screwy deal, you had to hold it just right in the sun to discern them. All part of the fun of a breakdown, $139.00 plus postage, (bit more than the Ebay price crane op posted, as expected.....) and it's on it's way. No way could I have read those dot numbers upside down with a borescope, so worth taking it off.
Only after ordering the part, on my third job of the day, I noticed that even without the PTO engaged, soon as I flick the switch in the truck cab to the crane throttle, after about 15 seconds the idle climbs and levels off at 800, normal is 600. No throttle action in the op cab via the floor pedal or the hand set throttles. The issue may be in the device/switch/relay, that's up in the truck dash (or wherever it is), and the op cab sensor I just ordered may not be the problem, but if nothing else, after replacing it I will at least know IT isn't the problem.
Short of extending the boom, which is usually the only time I rev it up as that mode is so slow anyway, once at work swinging trusses the 800 rpm is about fast enough, winch speed is good, boom up/down, rotate. The last job of the day no one even noticed. I set the 18 K storm tank all at normal idle speed, this morning I may try a work around: PTO engaged, truck throttle still on/engaged, so truck floor pedal working, and with me in the op cab extending the boom, have someone else in the truck cab with their foot on the throttle giving me about 1500 RPM to get that boom shot out, once out the work can be done just fine at 800 or even 600 rpm.