If you have a Lippert Power Tongue Jack Model # 181794 (It'll say LCI on the head as well) and it is acting up and is still under warranty, you may want to call Lippert and get a new one. This jack is rated for 2500# and they have had problems with the clutch failing so they have redesigned the unit with a new clutch and now it is rated for 3500#. I ended up calling Lippert directly because even though my trailer is still within the Keystone 12 month warranty, dealing with the Keystone dealers in my area is like getting teeth pulled and the thought of waiting up to ten weeks to get the problem fixed / replaced didn't exactly appeal to me. Seven minutes on the phone with Lippert and they are sending me a complete new unit within the week ... and they don't want the old one back (me gonna rape and pilage it for parts). Three bolts, one wire, twenty minutes and I'll be done with the replacement. And yes, there is an inline 30AMP fuse you can pull when parked, if you are so inclined.
well that's what I call customer service !! I talked to Lippert in Goshen, Indiana about my PTJ last thursday at about noon and the new one is now sitting in my front hall. With that track record I think they could probably consider a 30 minute or free policy !!