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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Luke Wilson on August 09, 2014, 04:12:57 PM

Title: Anyone have a master switch diagram?
Post by: Luke Wilson on August 09, 2014, 04:12:57 PM
Hey everyone,

Redoing the dash in our bus (1981 MC9), and wondering about two questions: (a) does it matter which post on the master switch various wires are connected to, and if so, (b) does anyone have a diagram or pictures of their master switch?

SIDE NOTE: I was supremely confident the day I took my dash apart, didn't document and label as well as I should have... feeling a bit overwhelmed now. Definitely a "coulda had a V8" moment! 😩
Title: Re: Anyone have a master switch diagram?
Post by: bevans6 on August 09, 2014, 05:04:51 PM
The MCI master switch is basically two gangs.  One is separate, and the other three positions are ganged together with a bus bar into one higher current capacity switch.  As long as you get them grouped together right, it will be OK.  The circuits that are on the separate bit are mostly the headlight circuits, everything else is on the ganged section.  If you google "MC-9 manual", you will find a link to a PDF version of the manual, the schematics are in section 7.  The master switch is on almost every page, showing all of the different bits of circuit that use it for switching on with direct power or through relays.

Brian