F53 Beeping

They are electric. I know the difference since I had the hydraulic on my 01 35U. I liked them.

Had that problem on my F53 Winne. It seems the jack fluid expands as the Temps go up. This will push one of the jacks down just enough to turn the warning buzzer on. The cure is, when bringing the jacks up don't shut the controller off. Just let it time out. As I remember 2 or 3 minutes. This bleeds off all pressure and worked for me. I think this tip was in the jack manual or Winne tip sheet.

On edit after reading above post by OP.

Are you sure about your jacks? I looked up the Specs for a 08 Sightseer 37 J and jack call out was "Leveling Jacks hydraulic, automatic controls w/remote"

You may have a later 08 or early 09 Winne. In that case you may have a "Level Best" jack controller and a Power Gear jack system...Still hydraulic. Double action jacks aka power down, power up.(No Springs)
But with some problems, search the forum under Power Gear.

My jacks are electric. No hydraulics like on our '01 Itasca F53.

About the only Ford installed alarm is if the E-brake is still on. No seatbelt, head lights on, check gauge and such alarm. I'm with Corkey05 and maybe the jack reservoir. Get a good angle on a climb or decent and all the oil moves to the front of back of the tank and trips the low level alarm. That is if you system has an alarm feature.

There's a chance the reservoir for your jacks needs topping off. Or that one jack didn't fully retract leaving the reservoir just below the "Low point alarm" sensor. If it's a little low the alarm usually doesn't sound of unless you're moving.