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Fifth-wheel and motorhome specifics

Fifth wheels level off the landing gear and have to find the hitch again. Motorhomes level through interlocks that keep the coach from driving off on its jacks. Know both sets of rules and most 'won't turn on' and 'alarm on the road' calls go quick.

The short version

Fifth-wheel front ends

Ground Control 3.0 landing gear are Hall effect legs with 19.8125 in of stroke and pinned inner legs. Chock the tires, pull the pins and set both inner legs 4 to 5 in above the ground. 'Drop front jacks' brings both legs down to the ground and stops, then Front lifts the pin box off the hitch.

Level Up uses 14K aluminum hydraulic landing gear, with the landing gear valve on the lead leg on a 4-point. In auto it drops the front below level, lifts back to level, levels side to side on the rear jacks, then extends the landing gear again to finish. Lippert's aftermarket manual calls for 12 in of ground clearance at the landing gear.

Ground Control TT uses a power tongue jack at the front instead, and it can't be moved on its own in manual mode.

Hitch recognition and auto retract

Both fifth-wheel systems remember the front height from the start of the last auto level. That only works if the front was above level when auto level started; otherwise the pad shows 'Feature disabled'.

Motorhome interlocks

Motorhome controllers check the chassis before they move a jack. When a pad won't turn on or won't auto level, prove each input before you suspect the controller.

InputWhat it wantsNotes
Park brakeSetPower Gear and Equalizer read a ground on the brake wire when it's set
IgnitionRun (HWH: on or accessory)Power Gear wants 12 V on its ignition input
EngineRunning (Lippert motorhome hydraulic)Keeps voltage up; auto needs 12.7 V
TransmissionPark, or neutral on a dieselPower Gear's neutral safety input reads 12 V or ground depending on chassis

Drive-away protection and air suspension

Release the park brake with the ignition in run and jacks down, and Lippert and Power Gear systems flash every light, sound the alarm and retract the jacks. Power Gear's emergency retract also fires on low fluid or a bad brake or neutral signal, so a flaky brake switch can retract a coach in the campground with nobody touching it. Pads time out after 4 minutes on Lippert motorhome and Power Gear hydraulic, 5 on Power Gear electric.

On air ride the bags have to come down or the jacks just stretch the suspension. HWH solenoid dump valves dump while you hold 'Dump' with the engine off; chassis pilot dump systems work engine on or off, and HWH auto mode dumps before it levels. Lippert lowers the bags at the start of a cycle and refills them on retract. Equalizer says start the engine and build air before retracting.

Jacks down warnings on the road

HWH's red jack lights come on at about 1/4 to 1/2 in of extension, and the dash light and buzzer run whenever the ignition is on with a jack out. Lippert and Equalizer watch retract pressure, so a warning while driving usually means a leak is letting a jack creep.

  1. Pull off safely and set the park brake. Equalizer says don't press 'Retract all' while moving.
  2. Walk the coach and look at every jack, hose and valve for fluid.
  3. No leak: pad on, press Retract, and wait for the light and alarm to stop. Look at the jacks again.
  4. Lippert: if it's leaking or keeps alarming, disconnect the pressure switch wires and go straight to a service center. Equalizer: a repeat on the same trip or within 24 hours needs service.
  5. In the shop: fluid level, then bleed (Equalizer calls trapped air the leading cause), then hoses, valves and cylinders. On Equalizer, slides retracted after the jacks can set a false alarm.

Ground, pads and support

Never lift the wheels off the ground to level, and never use the jacks to hold the coach for a tire change or for work underneath. Every maker here says it, and Lippert's service steps start with jack stands under the frame.

Lippert hydraulic jacks have a 9 in footpad on a ball swivel with a 12 in pad optional; Power Gear's shoe is 10 in. On soft ground, put load distribution pads under every jack and keep landing spots clear of holes and debris. The LCI Class C manual says past 1.0 degree front to rear you may need blocks or pads. Before it leaves, look at every jack: Lippert says confirm full retract by eye, and in cold weather check slides and steps too.

Careful: Never get under a coach held up only by its leveling jacks. Support it on stands under the frame first.

On the job

  1. Fifth wheel: chock, set the landing gear inner legs 4 to 5 in above ground (Ground Control), then drop the front.
  2. Start auto level with the front above level so hitch recognition saves a height.
  3. Motorhome pad won't turn on: park brake, ignition run, engine running, transmission in park or neutral, then the wire for each.
  4. Air ride: confirm the bags dump before leveling and air back up before driving.
  5. Jacks down alarm: fluid, bleed, then hoses, valves and cylinders.
  6. Soft ground: pads under every jack, wheels stay on the ground.
  7. Before release: walk around and see every jack fully up.

Numbers

Shop tip

On a motorhome that 'won't turn on', set the brake hard and watch the park brake light. A corroded brake switch or a bad ground on that wire looks exactly like a dead controller.

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