auto Levelers

All 4 should go down.

all 4 will deploy. the jacks are used to stabilize the RV in addition to leveling it. there may be a way to re-sync your system. check your owner's manual or contact the mfg.

Yes, of course all the levelers should go down. Did the 3 that went down raise the RV any? There's a risk of twisting the frame of they lifted it very much.

If you'd include some details on your RV and brand of levelers, you might get a detailed answer helping you understand where the problem might be.

“My wife and I disagree she thinks only the three needed will extend...”

Even the basic manual that came with your MH should have discussed frame twist that might happen with only three jacks deploying.

Kinda depends. Monaco only uses three. Regardless, all jacks should deploy when you press, level. So, if your coach has four, then all four should deploy when you level. Providing info on your coach, make model year etc AND any info on your jacks mfg including model if you have it, will greatly enhance any of the answers you may receive.....Dennis

Let me guess; Atwood electric jacks?

Just wondering, and yes, it would be helpful if you could tell us your make, model, and what jacks you have.

You must use all 4. If not you could bend your frame. You need proper support. It is like you standing on one leg for a long time. Not so steady...

Yes all 4 should deploy when using auto level. Since the fourth jack WILL go down in manual mode it might be a bad pressure switch at the fourth jack. Very easy to check. Also, welcome to the forum & please do add a signature so everyone can see what you have for more accurate help info.

Our motorhome is a 2016 Tiffin 32 SA with an HWH automatic hydraulic leveling system

DHall52 wrote:
Our motorhome is a 2016 Tiffin 32 SA with an HWH automatic hydraulic leveling system

IF, after trying to Auto level, the same jack refuses to extend at all, but WILL extend in manual mode, it would not be a pressure switch. The Pressure Switch only becomes involved once a Jack Touches the ground and
starts to raise the RV. When you manually extend that jack, does the RED led downlight come on? Also, YES, all 4 jacks should be on the ground when in Auto level on a HWH system, before the system shuts down.
For fun, here is the Service manual for your system. Are you waiting until the touch pad turns OFF after Auto leveling. Do all 4 red LED down lights come on? When all 4 jacks are extended? In Auto level just 3 red LED lights come on? Doug
https://www.hwhcorp.com/ml48380.pdf