While I was writing the update (grandkids visiting... multiple distractions!) and about ready to post, I saw Macwrench posted a reply about getting some info from American Coach. I decided to post this anyway as it may help others that are just starting to figure out how this leveling system operates and interacts with the coach air suspension system.
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Just ranting, but somewhere somebody knows how the jacks operate. I mean does the controller ground the circuit for the right rear jack and the jack go down? I have 12 volts on both sides of all 3 jack solenoid's.
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Let me share and add to the growing knowledge base.
I have poked around on my leveling system a fair amount as I had to repair it in 2016. I had an issue where my jacks wouldn't consistently retract. I still need to add what I did to my project thread but it wound up being a faulty circuit board. I was able to find a replacement control module ($150ish) as I couldn't find the issue on the circuit board.
I've done online research, did research by reviewing schematics, and following lines on my coach, watching how it operates, and have spoken with Bill at Power Gear. At the end of last month, I did some additional looking and testing.
I have the 500645 controller but I believe all the Power Gear controllers operate the same way. I also have the 3 jack leveling system with one jack in front and 2 jacks in the rear of the coach just behind the drive axle.
To answer your question Macwrench, the controller does ground the circuits. +12 is provided to the pump, the jack solenoids, and the jack dump valve (not to be confused with the air suspension dump valve!) through a common 10 amp line located near the pump reservoir.
If you put your voltmeter on the large connector that comes from the pump/solenoids (mine is the one in the upper left hand corner labeled pump harness connector) you'll see +12V on each solenoid wire. When you extend all jacks or retract the jacks the 3 wires from the solenoids drop to 0 (ground is applied) and the solenoids are energized. If the pump needs to run, a ground is applied to that wire.
If you're adjusting the level by using the front, left, right or back buttons on the keypad , then only one (or two in the case of the back adjustment) will energize. Of course, the pump is also running in these cases.
Summarizing:
Press the extend all key:
All jack solenoids are energized and the pump runs while the key is being pressed.
Press the front key to raise the coach:
Only the front solenoid is energized and the pump runs while the key is pressed.
Press the left key:
Only the driver's side solenoid is energized and the pump runs while the key is pressed.
Press the right key:
Only the passenger side solenoid is energized and the pump runs while the key is pressed.
Press the Back (or rear) key:
Both the left and right jack solenoids are energized and the pump runs while the key is pressed.
Press the Retract Jacks key::
All 3 jack solenoids are energized and the dump valve is energized. The pump doesn't run. The jack springs retract the jacks and force the hydraulic fluid back into the reservoir. The jacks extended indicator on the control keypad remains on until the float switch in the reservoir signals fluid levels have returned to normal full level.
While the above might be very elementary to some, I thought I'd spell it out for others that might be trying to figure out what happens when you press those keypad buttons.
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What I would really like to know is what tells the controller that the air suspension system can be activated?
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Moving on to that pesky auxiliary connector on the controller module that GleenLever asked about.
My aux connector is in the upper right hand corner. I only have 2 wires connected to it. A green one and a red one. The green is in position 2 and the Red on is in position 4. These wires run to the air suspension dump valve. The 12V needed to move the air suspension shuttle valve on my Freightliner chassis is not provided from the leveling system controller by comes from a chassis 12V source.
Keep in mind, the leveling control module is grounding the wires to energize things.
Last month we had a couple of days of nice weather so I went out and did some testing of that connector. Here's what I observed and will try to make this readable. I'll group each observation this way: Leveling System State, Green Wire reading, Red Wire reading and then other comments.
State: Ignition off, leveler off, jacks retracted.
Pin 2 Green: 12V
Pin 4 Red: 12V
Other: No grounds applied. Green and Red wire seeing 12V
State: Ignition on, leveler off, jacks retracted
Pin 2 Green: 12V
Pin 4 Red: 0V
Other: Leveling module is signalling the shuttle valve in the air suspension system to 'air up' by grounding pin 4.
State: Ignition on, leveler on, pushing the 'Extend all Jacks' key
Pin 2 Green: 0V
Pin 4 Red: 12V
Other: The red wire is no longer grounded and goes to 12V immediately upon pressing the all jack down button. This signals the shuttle valve to change position to dump the air suspension. You can hear the shuttle valve move with a noticeable click.
State: Ignition on, leveler on, pressed retract jacks key
Pin 2 Green: 12V
Pin 4 Red: 0V
Other: The red wire applies ground within a second or so of the retract jacks button being pressed. This signals the shuttle valve to change state and begin to air up the suspension.
To summarize the above detail:
When the jacks are extended, Pin 2 is grounded and Pin 4 is open to tell the dump valve to dump the air suspension.
When the jacks are retracted, Pin 2 is open and Pin 4 is grounded to tell the dump valve to air up the suspension.
This confirms what Macwrench posted.
Again, the detail is meant to help others understand their Power Gear leveling system. It also helps me remember how it works by documenting it.
Take Care!
Linear Mode
