I finally have my HWH 2000 series leveling system working correctly in all modes. It has been a long journey and I think others can learn from my mistakes.
I started last Nov first trying to verify all (4) of the HWH Leveling system fuses were good. (I now know that there are also several (12+) fuses in the basement control box, but luckily these were good.)
The next step was to check the Drivers control panel. The HWH panel is held in by 4 very small countersunk Allen screws with nuts on the back side (these nuts are inside the driver’s left side console). I had to unscrew and remove the entire drivers left side console panel to access the nuts on the backside of the HWH drivers control panel.
I found and repaired a broken ground wire on the control panel electrical connector. This wire was about 1” shorter than the rest of the wires and it pulled out of the connector.
I also removed the panel and sent it into HWH for testing and replacing the plastic cover.
Repaired ground wire on the back of drivers control panel
http://www.irv2.com/forums/f258/help...or-366256.html
After this repair I gained manual control over the leveling system (but not Auto). Prior to this I only had Travel mode.
I also replaced the HWH (Thomas) Auxiliary 12v air pump. This pump pressurizes the air bags when parked (and the main air tanks are depleted). The old pump was in very bad condition as they are exposed right next to the pass side rear dual tires. (Hindsight, but I think a Viair Industrial (250C-IG) pump would be a better choice than the open case Thomas. The Viair is sealed for harsh environments and has double the output of the Thomas.)
Replacing HWH (Thomas) Aux Air Pump
http://www.irv2.com/forums/f115/repl...mp-369684.html
A few weeks ago I reattacked the HWH leveling system and found the main leveling control box. It is located in the main storage basement attached to the ceiling between the frame rails. On the ceiling there is a large white Masonite board with the HWH control box, the Allison control box, and several other electrical boxes located here. I removed it and sent it into HWH for testing and repair. It is attached with 4 screws and U shaped brackets that clamp the box onto the ceiling. Once you get the plywood wiring cover out of the way, it only takes 5 min to remove the control box. I used a 10” long extension on my Phillips drill-driver to reach all the way down the side of the HWH control box. It has numerous wire connectors along the pass side and rear. They are color coded and fairly easy to disconnect by pinching the release. One note here, my system has one large green connector on the right rear that does not have a wire bundle connected to it.
HWH said the leveling sensor was bad and replaced the Sensor and sent the control box back. I reinstalled it and tested Auto level (you enter Auto Level by depressing the Air button twice). It attempted to work and my yellow level lights on the control panel now operated, but the system would go crazy and usually dump all the air from the rear and passenger side leaving the coach sitting on a severe slant. After several back and forth discussions, Joe Portelli at HWH a
figured out the new sensor had been installed backwards by his technicians. He sent me a new programmable leveling sensor that I had to install myself.
Installing a new leveling sensor: If you are reasonably handy with electrical components you can install a new HWH leveling sensor. Make sure you ground yourself before touching the box or any of the components. I removed the control box from the basement and brought it inside to work on. It is made with two rectangular aluminum cases joined in the middle with a large rubber band that holds them together. I removed the rubber band splitting the two cases apart. There are 2 ribbon cables and some wires joining the two cases. I set one case next to the other and left the cables connected. The leveling sensor is located in the top rear of the upper box. It’s a 6” long x 2” wide black plastic mount with a circuit board. The ½” black plastic hex that you use to adjust left-right level is part of the assembly. The hex head Phillips screw you adjust for Fore-Aft level also attaches to the leveling sensor. You need to rotate the ½” Hex nut which will rotate the Level Sensor ½ turn so you can access and remove the 3 screws holding the circuit board to the plastic sensor mount. There is also a 6-wire bundle that runs from the level sensor circuit board to an adjacent circuit board. The retainer for the wire connector was difficult to release so I used a small screw driver and then pulled the connector off.
The new Programmable Leveling Sensor has
4 Jumpers that must be set for the installed orientation as well as the leveling system type, hydraulic or air (see HWH programmable sensor instructions attached). For a Monaco application, place Jumper
JP1 in the closed jumper positon for AFT sensor orientation as well as jumper
JP3 to the closed positon for an Air suspension system. I installed the new sensor to the mount with the 3 screws and reconnected the 6 wire plug. Then carefully rotate the entire assembly using the black hex adjuster so the leveling circuit board will be in the up position when installed in the basement ceiling. It has a sticker on it that says UP (the old sensor had an arrow that said Forward and on mine it was pointing aft). You should also spend some time pre-leveling the box and sensor before installing it.
I then reassembled the two alum shells together with the rubber band around them and installed it into the basement ceiling. I reattached all the wire bundle connectors to it being careful to match colors.
Aligning the new Level Sensor: Now you can start the engine and pump up the air system. Place the HWH Level system in manual by depressing the Air button once and use the arrows on the drivers control panel and a good bubble level to get the coach level both fore and aft and left to right. There are also several smart phone apps to check level. Make sure you use 2-3 different places on the coach floor to check level. Then look at the HWH Drivers control panel. There are 4 yellow LEDs, one on each side of the bus depiction and one front and one rear.
If the yellow light is on, the HWH system thinks that side is Low. These lights are repeated inside the basement leveling control box, but in the Monaco installation you cannot see them because they are up against the ceiling behind a circuit board. Now you have go back and forth from the basement to the drivers panel adjusting the leveling senor to get all the yellow lights out. The ¼” hex screw adjusts Fore and Aft and the ½” plastic Hex adjusts Left and Right. (The screw also has a Phillips slot in the center, but I like to use a ¼” box end wrench for finer adjustment.)
This procedure is covered in detail in the HWH 2000 series instructions on page 7.
Quote from the manual:
The sensing unit has an accuracy tolerance of ± 5.4 inches front to rear and ± 1 inch side to side on a 36 foot vehicle. Typical leveling results will be better.
My technique for getting the leveling sensor alignment near perfect: Place a small mark at the bottom of the ¼” hex head Phillips screw with a Sharpie. Have a partner sit in the driver’s seat monitoring the four yellow Level lights (they should be out). Adjust the ¼” hex screw one direction until the yellow light just flickers on. Mark a spot on the black plastic base in line with your dot on the screw. Now turn the screw in the opposite direction until that yellow light goes out and the opposite yellow light just flickers on. Mark that spot on the base. Now you have an arc between the two dots. Center the screw mark in the middle of the two dots. Now you have found dead center for the front-rear leveling sensor. Do the same with the ½” plastic hex and set dead center for Left-Right. You may have to repeat this in a week or two after the system has settled in.
HWH is a great company that actually repairs what they sell and also offers technical help. If you want to send them a part for repair, call first and get an RMA number. They are fast in returning parts and their charges are very fair.
I need to thank K7JV, Paul at AZPete, and Joe Portelli for all the help in finally getting this system back up.
Hope this helps others.
Attach:
HWH 2000 Series 34296 instructions
Programmable leveling sensor instructions
Pics:
Leveling control box on counter
Pic of level sensor circuit board
Pic of sensor installed in control box
Close up of sensor mount (leveling sensor circuit board is on backside)
Linear Mode
