Multiplex Gremlins

[Steven Link]

I am having multiplex problems similar to Jvanloan's. Mine is somewhat different and I would appreciate any input from the group.  
Our girard patio awnings will spontaneously retract about 6 inches when we open or close the entry door. I suspect there is a ground problem with the magnetic door switches and the multiplex system but have been unable to trace the issue. Since the awing motors are AC 120 volt there has to be electrical or possible RF interferance.  I can reproduce the fault by passing a magnet over the door switches. Of course my fear is that the awinings will decide to extend while traveling.  This has never happened but the retraction problem is quite annoying.  
Dealer in Knoxville has been unable to diagnose or fix the problem after four tries.  Girard blames the coach multiplex.  Everyone wants to pass the buck...so you know where that stops...with me!  
Have replaced all awning control boxes ACMC & DCMC.  Still have the same problem.  I am going to the ground buss next.   Any Suggestions??? :X

[Joe Van Loan]

Does your multiplex system control the awnings?  The 2006 Patriot has manual switches to control the awnings.  Also, does your coach have one or two door switches?  If so, is one or the other or both causing the awning to retract?  The Patriot has two switches, one for the step and the other for lighting control.

Both switches have splices inside the wheel well on the Patriot.  I have had problems with water causing corrosion and high impedance in those splices.  I've respliced them and tried to water proof them.  You might check there.  They may be creating a voltage spike when opening and closing, especially if they are switching inductive loads, such as the step motor.  If so, you might install a high value capacitor across the switches to supress the voltage transient.

If the awnings are on the multiples system, it is unlikely door switches are triggering the awning control from the input/control side, since each panel issues a series of coded pulses to activate the control function.  The likelyhood of a voltage transient creating the right code is low.  In the Patriot, all the control modules are located in the rear closet.  If the awning is controlled via the mux system, are all the modules in the closet or are they located near the door switches?  It seems unlikely that a voltage spike could get all the way to the back closet.

Let us know if that helps.

[Steven Link]

Have 2 switches on the door but one has no wires to it all, so I removed it. Looks like when they built the coach they used a patriot door but everything(lights, step control etc) runs through the one switch. Connections do not seem to be corroded but I did not disconnect and seal them with dielectric grease. I will try that next or use waterproof 3-M splices. The door switches definitely go thru mux...somehow.  Same problem occurs occasionally when I open the first bay door on the passenger side. This door has a switch for the outside TV that cuts power to it when the door is opened. Don't know the relationship to the awnings other than thru the mux. The tv raise and lower function is 120 v like the awning motors.
Yes I do have the two hardwired switches to the awnings but also have a remote control with 8 chanels to control the awnings, light bar in the awnings and curtain in the awnings. All the 12volt stuff in the awnings works fine, it is just the main 120 v ac motors that are having the problem. (main retract and extend)
Checked the ground block in the rear and everything seems fine there.
Awinings are controlled by 4 boxes from Girard in the cabinet over the passenger seat. Have replaced all four of those boxes and reprogramed them. Girard sent all new boxes. Two are AC boxes to control main extend and retract and two re DC boxes to control the lights and curtains on the awnings.  TOO MUCH ELECTRONICS!  Of course Girard blames the MUX system for stray RF.  I just don't know how this is possible???

Thanks for the reply. I will let you know how it goes.
Steven Link

[Joe Van Loan]

More questions!  You mentioned the same thing happens when you open a bay door.  Are there any wiring connections or switches at the door?  There should only be leads for lock/unlock mechanism, unless your coach has an alarm system.  I'm wondering if there isn't some mechanical vibration causing the problem.  I realize a magnet at the door switch tends to eliminate that pobbibility.  Our Patriot must have a lighting control module to control the time-out of the bar and "porch" lights.  Maybe that is the connection to the mux system you mentioned.

Can you isolate control functions on the Girard boxes?  If they they connectors, you might try disconnecting all connections, one at a time,  execpt the 120 V to the awnings.  How many awnings are controlled by the two boxes?  I understood only one awning is retracting.  Does it have its own box or does it share with another awning?  Can you disconnect the DC boxes and see what happens then?  Anything to isolate the source of the "trigger" should help identify the source.