cruise control
I just got through repairing the almost same problem on my 1993 Fleetwood Holiday with a G30 Chevy 350 V8 chassis.
On mine, the turn signal/cruise control stem seemed intermittent... had to "fiddle" with it to get cruise to engage, and then cruise would "fade", especially when pulling hills.
I found a replacement control stem, with all new switches, for less than 40 bucks at:
http://www.1aauto.com/1A/Electrical/ChevyTruck/VanFullSize/PLP2310851/40419
This new arm solved the intermittent problem, and it is an easy pop-out push-in replacement. The RV cruise worked better, but would still fade out when pulling hills. I tried to find a replacement actuator assy ( the throttle-pulling assembly mounted on the drivers side just behind the carburetor ) but the only ones I could find were over $300.00 (Friendly local Chevy parts dealer).
I took mine off, just 3 screws , unhook the throttle-puller link wire, a small electrical plug, and 2 vacuum hoses. I carefully disassembled it and didn't find any cracks in the rubber diaphragm or O-ring holding things together. I did note, however, that about 4 chrome-looking wires (that make contact with the diaphragm) were a bit scuffed and corroded. I cleaned them as bright and shiny as I could, and reassembled it carefully. It now works GREAT, and pulls hills without fading, even downshifting when pulling hard enough instead of just lugging down and fading out and dropping out.
Having working cruise control REALLY improves the driveability of the RV... makes it almost a pleasure instead of a white-knuckle endurance experience.