I can't answer exactly, perhaps someone will come along with first hand knowledge but here's the 3D Parts list for the 2002 Sightseer 30B. You'll find the Jacks diagram on page 46 of the 210 pages of the parts list.
You need to provide more info, as well. Do you have a Ford or Workhorse chassis?
https://www.winnebago.com/Files/File...GO/2wfd30b.pdf
On 20-year old systems I don't know if they work like newer systems but many of the newer systems do not have jack sensors at all. The just have a float switch in the hydraulic fluid reservoir. If the fluid is low the float switch assumes the jacks are down. For those types of systems retracting all the jacks and making sure the hydraulic fluid is completely full will allow the Jacks Down sensor to turn off.