In two previous RV's I've owned (Forest River Class C Sunseekers), the crank on the bedroom vent went POOF and wouldn't work. Both times I have replaced it, I went to RV dealers and it cost me the $100 deductible on my extended warranty (and who knows what it REALLY cost).
I could not figure out why a mere CRANK would cost that much money. But stupid me, didn't question it. Just paid it. Or when I did question it, I got "gobblety goop" from the RV repair department and they didn't tell me the real story.
Well, on my current RV (2013 Sunseeker 3170), the BATHROOM vent crank went poof, quit working. I'm in Iowa right now. Found a guy who kind of does mobile RV work on the side, he works full time at a regular RV dealer.
He thought he could just get the crank, but every one he tried wouldn't fit. Well, he found out that that once a model year is "past" the parts are obsolete. He said that the entire vent including the fan (since it's my bathroom) would have to be replaced. (which explains why I had to pay $100 deductible in the past for "just a crank") No problem getting an entire vent to fit, just can't get "only the crank."
But the guy, bless his heart, thought it was totally stupid to have to buy an entire vent for just a crank. So, he found a "twisty" handle
(this is what I mean: Replacement Operator, Knob and Screw for Ventline Ventadome Trailer Roof Vents w/ Wedge-Shaped Dome Ventline Accessories and Parts BVD0462-00
he tried it, and it worked! I like it much better! The guy did caution me that this may work and won't need anything further, or it might not. So for now, I'm just going to see if it will work.
Note to FOREST RIVER: Why don't you put "twisty handles" in the bathroom and bedroom vents, like the handle in the front vent? I have had problems in every RV I've owned with "crank" handles.
Another note: I'm past dealer warranty, and didn't get extended warranty this time, so putting the twisty handle on doesn't void anything. If it doesn't work, oh well, I'll just get a new vent. Took the guy six visits to figure this out. I paid him $50 for his time.