Sounds like you know where the control is located and have pulled some wires? That is a good start but this is a totally different systems than many older RV use, so will take a different testing process!
Looking at the parts catalog here:
https://catalog3d.winnebagoind.com/menu/Parts.htm
I see no 34 foot, so maybe do some check for the exact model number for the RV? I went with 33c as being likely correct but that may need checking if you don't find what I'm seeing!
Click these snips for better view!
Correct location on back wall of wet bay?
If correct, the part number is this:
Doing a search for that part number turns up this info:
https://www.precisioncircuitsinc.com...tch-to-ground/
Brochure is listed at right side and explains operation far better than I might, so do a look there and then there is a troubleshooting guide.
Short story as I see it is that any time one of the switches is pushed, it puts a momentary ground on the wire going to the control. If all is well with the control, the momentary ground will toggle the pump on/off each time a switch at any location is pushed, putting ground on that wire. Simple stuff like all solid state----if it works!
Sounds like we can move beyond a wiring issue at the control as the pump works and stops/starts when you remove the ground coming from the switches. Is what I read what you meant?
If true, my best guess would be that there is a ground somewhere along the wiring from all the switches to the control. When you pull the wire off, the control is seeing that as one of the switch toggle the command, so turns on/off to follow.
Basic idea is that each time you pull the wire off, that removes the ground and then when put back it adds ground back.
So a hunt for the full time ground on that wire is needed as it should be momentary, not full time!
A stuck switch? Or a wire defect like one mashed onto ground somewhere?
Bad control? I don't think so!!!
At each end of the wires, there should be a code:
This wire ID should be found here to help find which wire is which?
https://www.winnebago.com/Files/File...ical_guide.pdf
Good luck with the chase!