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Topic: HWH question - Coach raises on it's own (Read 747 times) previous topic - next topic

HWH question - Coach raises on it's own

So, on our last trip we were parked in a very level spot.  I leveled the coach and left the leveling on.  The second day I stepped out of the coach and almost fell.  It was a long way down.  For some reason the entire coach had raised probably 4 inches.  I started the coach and leveled it again, two days later the entire coach had raised about 4 inches again.  After that I leveled and turned HWH off.
I have a call into HWH but could be a couple weeks.  Just thought I would throw it out to see if anyone had seen this problem before. 

Re: HWH question - Coach raises on it's own

Reply #1 –
If air is somehow getting (incorrectly) into ALL the bags during Auto Level, then it is going through (or past) the "raise" solenoids.  You have 2 raise solenoids on each 6-pack manifold.  Since it is very unlikely all 4 have (mechanically) failed simultaneously, your problem is probably a incorrect signal from the control box (HWH CPU).

Best way to isolate problem is to follow trouble shooting steps in HWH Service Manual.  If you have the 600 Series, link below.

Follow the steps exactly as written!  Do not skip steps.  Do not "assume" something is OK until you check it.

https://www.hwhcorp.com/ml11148.pdf

Re: HWH question - Coach raises on it's own

Reply #2 –
Thanks for posting the manual.  I will go through the troubleshooting and see if anything turns up.

Re: HWH question - Coach raises on it's own

Reply #3 –
First thought - one of the raise solenoids is leaking through causing part of the coach to raise.  Then the HWH system comes on to check level, finds the coach isn't, and adds air to the low sides.

BTDTGTTS, with thanks to Mike Rash and Jerry Whiteaker for the correct diagnosis after no one in Nac could figure it out.  Leaning Coach, Air Check Valves

Re: HWH question - Coach raises on it's own

Reply #4 –
Michelle,
That makes alot of sense. Im now trying to figure the easiest way to determine if that is what is happening.  It has to be slow because both times it took until the second day to realize or notice what had happened.

Re: HWH question - Coach raises on it's own

Reply #5 –
Quote from: Green99 –
That makes alot of sense. Im now trying to figure the easiest way to determine if that is what is happening.  It has to be slow because both times it took until the second day to realize or notice what had happened.

Level the coach, measure and record the height of each airbag (between the plates), shut the leveling system off.

Repeat measurements every hour or so (for a slow leak, every few hours would be fine).

The leak-through corner should show itself as an increase in air bag height (if there is enough pressure in the tank)

Alternatively, you can leave the leveling system on, but you're going to need to measure before the system wakes up to relevel, and a small leak is going to be hard to find.  You might need to monitor the panel when it wakes up, too, to note which corners it thinks are low (the one that's not low would be the leak-through one)

Re: HWH question - Coach raises on it's own

Reply #6 –
Quote from: Michelle –
Level the coach, measure and record the height of each airbag (between the plates), shut the leveling system off.

Repeat measurements every hour or so (for a slow leak, every few hours would be fine).

The leak-through corner should show itself as an increase in air bag height (if there is enough pressure in the tank)

Alternatively, you can leave the leveling system on, but you're going to need to measure before the system wakes up to relevel, and a small leak is going to be hard to find.  You might need to monitor the panel when it wakes up, too, to note which corners it thinks are low (the one that's not low would be the leak-through one)
Michelle,
 I am just starting to understand the HWH system, but if the system is left on why wouldn't it try to lower the corner that is high, rather than adding air to the other 3 air bags?

Re: HWH question - Coach raises on it's own

Reply #7 –
Quote from: craneman –
Michelle,
 I am just starting to understand the HWH system, but if the system is left on why wouldn't it try to lower the corner that is high, rather than adding air to the other 3 air bags?

It will initially try to lower it, but if it doesn't respond adequately, the next thing the HWH system does is raise the other corners to compensate.  That is what happened with our coach.  In fact, when the aux compressor would come on to raise other corners, the one with the leak through would raise as well, eventually to the full extent that corner could inflate.

Which reminds me - if the high corner won't lower, check the 6 pack manifold exhaust port (hole) for a blockage.  Dirt daubers love to build nests in them.

Re: HWH question - Coach raises on it's own

Reply #8 –
Quote from: craneman –
...if the system is left on why wouldn't it try to lower the corner that is high, rather than adding air to the other 3 air bags?
Have to side with Chuck on this one.  Even if a leaking "raise" solenoid on one corner instigated the OP's rising coach problem, what are the odds that the "lower" function on that same corner would also simultaneously malfunction, preventing the HWH system from releasing air?

Following the Trouble Shooting Guide as I suggested (Reply #1) would quickly identify a blocked exhaust port, faulty "lower" solenoid, or bad wiring harness.

I will be interested to hear if the OP actually follows the recommended trouble shooting steps, and what is the result.

Re: HWH question - Coach raises on it's own

Reply #9 –
Chuck,
After going through the trouble shooting steps here is what I have found so far.  When testing the yellow lights, I could not get the rear yellow light to come on by lowering the rear and raising the front, so I will have to test the wiring at the sensing unit.  (Is this mounted under the floor of the coach}
Also, I found it odd that I had been running the coach up and down to check the yellow lights and after a certain amount of time the HWH just shut off.  The air was down to about 50lbs on the gauge(makes me question if the air compressor is running) I plan on checking that tomorrow as well.  I started the coach let the air build up before starting to verify I couldn't get the rear yellow light on, and again there was a point the unit just shut off.  I don't know if this should be considered normal.  I plan to try to find time tomorrow to test the pins for the yellow lights.
I guess my question is that in my mind I am not sure how that would explain the coach raising on it's own, but I also know that sometimes fixing what you know is wrong will take care of other issues.
thanks again

Re: HWH question - Coach raises on it's own

Reply #10 –
Quote from: Green99 –
1.  ...so I will have to test the wiring at the sensing unit.  (Is this mounted under the floor of the coach}

2.  The air was down to about 50lbs on the gauge(makes me question if the air compressor is running).

3.  Also, I found it odd that after a certain amount of time the HWH just shut off. 
1.  My level sensing unit is mounted inside the coach, screwed to the floor under the sofa on driver side.  I have also read about them being mounted on the floor under a kitchen cabinet, and below the coach floor, hanging from the "ceiling" of a storage compartment.

2.  If the HWH system is "ON", and the system air pressure is down to 50 psi, and you push the "raise" button or a "UP" button, then the HWH aux compressor should run.  If it does not, check the fuse at the compressor.

3.  When you say "the HWH just shut off" do you mean the "SYSTEM ON" light on the touch pad went out?  Just like if you had pushed the "OFF" button?  Depending on what sequence of buttons you had pushed, this may be normal, or it may indicate a intermittent loss of power to the touch pad.  If you have the touch pad powered "ON" and are actively pushing buttons, then it should not shut off all by itself.
 

Re: HWH question - Coach raises on it's own

Reply #11 –
Update:  After going thru the HWH test procedure.  One problem I was able to identify was that either the wiring or the level sensor is bad.  I am not sure this could cause the problem described, but I don't think the auto level function can work if it doesn't know when the rear of the coach is low.  I am waiting a call from HWH and will post results of the call if anymore info. is obtained. 
Thank you all for the help.
Jerry