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JDL · 12-24-2012, 07:32 AM

Going through my 2000 Monaco Windsor, I found a small electric air compressor above the front axle. I also noticed that both air tanks have pressure switches, which I assume are used to switch on the electric air compressor. My coach has the optional air leveling system in place of the hydraulic system. I assume this air compressor was in place to pressure the system for long term parking/leveling. All this being said, I am probably the first person to look at this thing since it left the factory.

Anyone have any information on this unit? I plan on making it work again, it currently is not running, although air pressure is below 40 psi on the main system.

Thanks in advance.

djhinds · 12-24-2012, 08:01 AM

On my 2004 Signature the small air compressor is used to keep the coach level. It only fills the air bags not the front and rear air tanks. You can tell if it works by taping the brake pedal till the air gauges read 0. then have somebody real close to the compressor while you turn on the key and push any up button on the level controller. Mine is real quite and I have to be close to hear it. My compressor is just ahead of the rear axle on my coach.

Dave

Burgy · 12-24-2012, 08:18 AM

You will probably find that it is DOA those HWH compressors are not sealed and they fail within a few years.

This is what I replaced mine with, you can get it from many vendors and in different versions (smaller). Just be sure to run a dedicated power wire and using a relay triggered by the old compressor power lead.

VIAIR 450C Air Compressor Kit at The Home Depot

lonestarace · 12-24-2012, 11:14 AM

Quote:

Originally Posted by JDL

Going through my 2000 Monaco Windsor, I found a small electric air compressor above the front axle. I also noticed that both air tanks have pressure switches, which I assume are used to switch on the electric air compressor. My coach has the optional air leveling system in place of the hydraulic system. I assume this air compressor was in place to pressure the system for long term parking/leveling. All this being said, I am probably the first person to look at this thing since it left the factory.

Anyone have any information on this unit? I plan on making it work again, it currently is not running, although air pressure is below 40 psi on the main system.

Thanks in advance.

Especially p.11 of this pdf file
http://www.hwhcorp.com/ml13985.pdf

JDL · 12-24-2012, 01:29 PM

Thanks everyone for the prompt replies. My unit is DOA. I will sort out the relay and additional wiring to install a better unit. I like the VAIR unit.

I did have the HWH manual, for some reason, I missed the "alternate air compressor" option.

Those of you with this system, what is your setup routine when arriving at the campground?

I havent parked it other than at home, but I believe I would do it this way.

Safely park the coach. (leave the engine running)
Verify, no obstacles underneath, then slide out.
Dump air from the system until the coach approaches bottom, then set the auto air level and let the system level out.

I am looking for the most stable camping setup. Does this seem to be normal??

Thanks again.

Craig_R · 12-24-2012, 01:51 PM

Quote:

Originally Posted by JDL

Thanks everyone for the prompt replies. My unit is DOA. I will sort out the relay and additional wiring to install a better unit. I like the VAIR unit.

I did have the HWH manual, for some reason, I missed the "alternate air compressor" option.

Those of you with this system, what is your setup routine when arriving at the campground?

I havent parked it other than at home, but I believe I would do it this way.

Safely park the coach. (leave the engine running)
Verify, no obstacles underneath, then slide out.
Dump air from the system until the coach approaches bottom, then set the auto air level and let the system level out.

I am looking for the most stable camping setup. Does this seem to be normal??

Thanks again.

That is the same procedure we use and it does provide the most stability.

Mike Canter · 12-24-2012, 04:35 PM

JDL the Thomas 12 volt air compressor that is used is of a very good quality and is normally used in dental offices for air or vacuum. What causes them to fail is that they are exposed to the elements hanging under the MH and that is going to be the same problem for any compressor. The motor part of the compressor has to be vented for cooling because they may have to run for a long period of time and road grit gets into those vent holes. When I replaced mine I built a galvanized sheet metal box with vent holes to go around the whole unit. Now it stays clean.

Have you actual pulled the whole unit out and checked it? There is a pressure switch and a relay on the unit that can fail. The first time mine stopped was because the power line plug close to the unit was loose. Did you test the whole system as I posted earlier in this thread? There is also a fuse and a logic circuit that can be checked by watching lights on a HWH panel while doing the test I posted.

moisheh · 12-24-2012, 06:18 PM

You should not have to dump the air. Just turn on your auto levelling.

K7JV · 12-26-2012, 08:40 PM

Our air compressor failed, as well. I called HWH and purchased one from them, which installed fairly easily, and all has been good since. Other responders are right, though. Be sure the pressure switches and controls are working properly. The total cost for the compressor alone was roughly $460.

I also agree with just activating the automatic leveling function, to level the coach. The "book" suggests extending the slides, first, which requires shutting down the engine. The key can then be put in the "ON" position, without re-starting the engine, to energize the HWH system and initiating the auto-leveling function. Once the auto-leveling function has started, you should be able to turn the key off, and the process will continue until the coach is level. The system will lower the high end/side, first, by dumping air. It will then add air from the front and rear tanks to complete the leveling as needed. The air compressor you are talking about provides the needed air once the front and rear tanks pressure drops to the point where they will not longer do the job. That normally doesn't happen during the initial leveling, but only after air has been subsequently used for tweaking the level, over time.

On our coach, the front left corner has always had a tendency to slowly "bleed" down, so the air is needed, from time to time, to keep the coach level. The system does this automatically, as long as the keypad isn't actually turned "OFF". Also, for that reason, when we park for storage, I dump the air system so that the one corner won't go down by itself. If you do this, be sure that the parking area is quite level, otherwise doing so might cause the chassis to twist as it settles down on all four corners.

The HWH system is really very well engineered, and works pretty reliably. But like so many systems on these rigs, they can malfunction. Fortunately, the HWH troubleshooting information available on the Internet, on this forum and even from HWH themselves, will help folks with good technical and mechanical skills to keep them working over the long haul.

Mike Canter · 12-26-2012, 09:51 PM

I bought a brand new Thomas compressor on eBay for $70. It was identical to the one Monaco uses. If you don't build a box around it will fill with road grit and fail again.

rex · 12-27-2012, 09:43 AM

JDL, also make sure you don't have a blown fuse that powers the compressor. The fuse could be in-line near the compressor or in a basement bay where other fuses are located. All the wiring to the compressor is 12v dc positive - NOT ground. Ground is through the frame of the compressor mount to the chassis.