Stereo Wiring Diagram Needed for MCI-9

[brianzero]

Hi All,

I need a stock stereo wiring diagram for an MCI-9. I have the speaker diagram provided by the manual, but for some reason there isnt a stereo wiring diagram. I'm hoping that the stock stereo is 12v so I dont have to 'find' a 12v source in the drivers compartment.

If this isnt something that exists (the wiring diagram) I can figure it out with a multimeter, I just figured the diagram would be a help.

[bevans6]

99% sure it was a 24 volt unit, mine was anyway (1980 MC-5C)  Stud 55 in the front electrical bay is where you would find a 12 volt source, if it's wired in your bus (was an option) and if no one has taken it out.  If it's there, there is a 30 amp fuse in a little twist cap fuse holder on the upper right side of the battery bay, just behind the door.

[brianzero]

I suspect mine is the 24v unit as well.

Here's a really stupid question about Stud 55 that Ive been wondering about. I know it's 12v positive, but where do I get the 12v negative?

[ol713]

Hi;
   Almost any piece of metal will do for a ground return.
                                       Merle.

[Iceni John]

Don't all DC negatives, regardless of their voltage, return through the frame to the batteries?   Because steel bus frames are not the best electrical conductors, it could be prudent to use a separate negative conductor, i.e. use 2-conductor copper wire instead of just one red positive, at least for the larger DC loads.   (I'm doing this even for my water pumps that draw only about 7 A each.)   It's no more work to run this 2-conductor wire, and as long as it runs without interruption from source to load without intermediate splices or connections it should be more reliable than using the frame as a return, and produce less voltage drop.   Just make sure the wiring is sized for no more than 3% voltage drop under full load, and ideally less than that.

John

[bevans6]

What 12v load are you planning to install?

Brian

[brianzero]

The load (as defined on the website) is:

Maximum Power Supply Current / DC5V=1A

The unit is a Kenwood DNX 571:

http://www.kenwood.com/usa/car/navigation_multimedia/dnx571hd/index.html