Bobby
I have dealt with the multiplex system several times. It would be helpful to know what problem you are having. There is a chassis multiplex system which is basically the driver and passenger function switches, the there is the coach (house) multiplex system which is manufactured by Intellitec. The technical helpline is 419-965-3014. Chris and Mark Bayus (M&M electronics) provide the technical for Intellitec. I talked to Chris recently and he was extremely helpful and knowledgable on the Intellitec multiplex system.
Please pass on the problem you are having to benefit those of us that have the same system.
Thanks, Larry D