11-22-2025, 06:18 PM
Find the module that controls these functions. It should be all in the same module. The relays that control all these functions should be controlled by that module and should be close to that module. I’ll bet you’ll find there’s a bad/poor common ground involved with these functions.
When I say “module”, I’m referring to what ever unit that carries out the actions told to it by the multiplex control computer.
In my coach that has a multiplex system, there are only 3 locations for these “acting modules”. These take a very low amperage signal and convert it to a higher voltage through relays that actually do the switch on or off. The neat thing about a multiplex system is the ability to put any action (turn on/off a light, an ac, a generator or anything that can be switched) in any location in the coach. Additionally, only a few (3 wires on my coach) run from each switch panel only to the system computer. Only a few wires also run to each action module.
The downside is the added complexity of the additional relays and grounds needed to do said action.
One confounding factor I’ve found in my coach is the system is 12V, but my chassis is 24V. The step down dc to dc converter needs to produce very clean power or the entire system acts VERY poorly. I do not think that is your issue here, or at least it would be way down the possibility list- unless you’re seeing some other oddities (switches need a couple of pushes to stay on/off, for example).
When I say “module”, I’m referring to what ever unit that carries out the actions told to it by the multiplex control computer.
In my coach that has a multiplex system, there are only 3 locations for these “acting modules”. These take a very low amperage signal and convert it to a higher voltage through relays that actually do the switch on or off. The neat thing about a multiplex system is the ability to put any action (turn on/off a light, an ac, a generator or anything that can be switched) in any location in the coach. Additionally, only a few (3 wires on my coach) run from each switch panel only to the system computer. Only a few wires also run to each action module.
The downside is the added complexity of the additional relays and grounds needed to do said action.
One confounding factor I’ve found in my coach is the system is 12V, but my chassis is 24V. The step down dc to dc converter needs to produce very clean power or the entire system acts VERY poorly. I do not think that is your issue here, or at least it would be way down the possibility list- unless you’re seeing some other oddities (switches need a couple of pushes to stay on/off, for example).
06 M450LXi 3 slide