Jacks Down Alarm and Light – Mitigating The Loudest Alarm Module In My Coach

As the title states our coach has a very loud jacks down audible alarm.  In a diesel pusher this alarm serves as your “put the jacks up before you move the coach, you “dumb-ass” alarm. It has both a audible (under the dash) and lighted alarm (on the dash).  In our coach the alarm is ear piercing. No, really it is, and many others have this complaint as well.  The intent of the alarm of course is to make you put the jacks up prior to moving the coach. The problem with the intent of the alarm is two fold. First you cannot warm your diesel engine without the alarm blaring and second, it is so loud that even with my 67 year old ears I can hear it from outside the coach.  Something had to be done.

Knowing where the alarm module is located and that it either modified to switch it on or off or at the least it needed to silenced or muted somewhat is what drove this project.

To that end I started with google searches on the subject and found out I was not the only one that though the audible alarm was too intrusive.

First I had to know the location of the circuit board so I could find the correct fuse/s that allowed power to flow to the audible alarm.

In the case of Class A coaches you will find that they have about as many circuit boards, fuses and circuit board locations as the International Space Station. finding the correct board and wiring schematic was the first order of business.

I eventually got advice from the [url=http://www.irv2.com/forums/]iRV2.com[/url] (an enthusiasts website) and was able to determine that the circuit in question was located directly in front of the driver and was accessible through a hatch in the dashboard.

 
The schematics told me that the fuse was F-15 on the circuit board. For a fleeting second I thought I would just pull the fuse and perhaps that would silence the alarm and leave the large red “jacks down” light burning. No such luck.  Next I thought I would trace the wires from this fuse and put a simple single pull single throw switch in line to turn the audible alarm off and on.  I determined that given my history of being ready to drive before being “actually” ready to drive should be of concern. So, I nixed the switch.
 
Next, I had read on IRV2 that several other coach owners decided to “mute” their alarms with multiple wraps of electricians tape to get the sound to an acceptable level of not making their ears bleed.  I opted to try this.   So the search began for the speaker module. As you can see from the above photo there is a lot gong on under the dash.  After about 40 minutes of subjecting my ears to the damn alarm I finally found the stupid thing. It was about knee high in front of the driver on the left side of the steering column all the way up on the firewall behind about 6.7 billion wires. Not easy to get too. I had the ignition on and off many times while trying to locate this beast.
 
After contemplating the best approach to wrapping tape around and over the module I noticed that the module (two inches in diameter) had what appeared to be a series of triangles on a movable plate that was attached to the noise modules face. I reached in, and rotated the plate until the solid portion of the little spinning dial covered the triangular portions of the noise maker module below it. This effectively closed off the area where noise could come out. Could it be that easy?  I turned on the ignition switch and the noise maker was barely audible.  
 
Success!  I killed the noise.  All without a switch, solder, soldering iron or electricians tape, cut or burned figures and no injuries to the existing wiring……   Wooohoooo! It’s good to the king.
 
Next up?  New black water and grey water knife valves and repairing my black water clean out sprayer circuit (it has a bad leak when trying to use it).