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Topic: 2003 U320 Level Sensor too Sensitive - Replace, Fix, ???? (Read 970 times) previous topic - next topic

2003 U320 Level Sensor too Sensitive - Replace, Fix, ????

I believe I've read every post on this forum and have not seen the problem I have (of course somebody will point to the one post I missed). 

My level sensor is too sensitive to front-rear level.  Try as I might, I cannot adjust the sensor so that both front and rear yellow lights are out - there is always one lit.  Just by tapping on the sensor adjustment nut with my finger causes the front-rear lights to blink one-after-the-other.

Any bright ideas.  Yes, I know I can just buy a new one; but is there something I'm missing?

My sensor is the electronic one mounted inside the HWH control box with the adjustment nut and screw on the outside of the box.

Jim

Re: 2003 U320 Level Sensor too Sensitive - Replace, Fix, ????

Reply #1 –
Jim,

There is a troubleshooting section in the HWH manual (if you don't have it, I think it's this one http://www.foreforums.com/index.php?action=media;sa=item;in=1459 )

In ours, the page marked MI91.232M discusses sensing unit diagnostics.  With a test light you can check to make sure the sensing unit and the control box are both working correctly.

Re: 2003 U320 Level Sensor too Sensitive - Replace, Fix, ????

Reply #2 –
Thanks Michelle. 

I have been through that procedure and it doesn't help.  It's just that my sensor is so sensitive that if you gently tap on the adjustment nut with your finger, the led's (both on the sensor board itself and those on the leveling pad) jump around - front low, back low, passenger side low, driver side low. 

I found a really detailed description of electronics in HWH systems that include many additional diagnostics.  Also, lots of other useful info.  The document appears to be a training document.  Here is the link:

http://www.hwhcorp.com/Electronics_and_HWH.pdf

I've taken the sensor board out and looked for cold solder joints or any other thing that might indicate a poor connection.  Also, wiggled all connectors.  Nothing peculiar jumps out at me. 

I've tried switching the 110/220 switch they use to select enhanced sensitivity and it makes no difference.  It's like mine is stuck in the enhanced sensitivity mode.

I note that the enhanced mode switch is wired to the main board and not the sensor board, so I surmise that the "command" to go into enhanced mode must come from the main board to the sensor board.  This could indicate that the problem is with the main board and not the sensor board. 

Me thinks a call to HWH is in order.

Jim

Re: 2003 U320 Level Sensor too Sensitive - Replace, Fix, ????

Reply #3 –
Jim, thanks for the link; good info.
Sounds like you are really on top of this. Am guessing you already looked at the sensor adjustment sheet 47508 (http://www.hwhcorp.com/ml47508.pdf) and 47509.
I have not had to deal with this, but in case I do where is this sensor located?
Hope you post final solution.
Dick

Re: 2003 U320 Level Sensor too Sensitive - Replace, Fix, ????

Reply #4 –
My sensor is mounted in one of the HWH aluminum boxes with the Plexiglass windows.  It is the one closest to the bay door. 

In my opinion, the mounting is rather poor.  The sensor board (it is a circuit board, not the turtle shaped thing in the older coaches) is mounted on a piece of aluminum angle and is fairly flimsy.  Just driving down the road results in the sensor board jiggling around and could easily move out of alignment.

Jim
 

Re: 2003 U320 Level Sensor too Sensitive - Replace, Fix, ????

Reply #5 –
I replaced our level board once (it was identified as bad, but it turned out to be fine so its now in my spares bin) ...

Agree that the mounting is less than inspiring ... thankfully I've never had it go out of adjustment in spite of the fine efforts of the interstate system.  It is as you noted, very sensitive, mostly due to the mounting, but once you "average" it in place it seems to hold just fine.