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hojji firemaker (Hojjifiremaker)
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Username: Hojjifiremaker

Post Number: 31
Registered: 4-2008
Posted From: 67.142.162.38


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Posted on Sunday, September 20, 2009 - 12:00 am:   

How do I wire a 12 volt car stereo in a 24 volt MCI Bus?
Our coach unfortunately did not come with one pre-installed, There must be a way, and it can't be that hard...
Fred Nelken (Faster_freddie)
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Username: Faster_freddie

Post Number: 44
Registered: 1-2005
Posted From: 70.213.39.182

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Posted on Sunday, September 20, 2009 - 1:53 am:   

The MCI comes from the factory with two 12 volt posts in the outside electrical compartment under the drivers window. Take a look in the manuals, or call MCI or a bus garage and they can give you the post/pin numbers. Just run the power to one of those posts.
Roger Baughman (Roger)
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Username: Roger

Post Number: 129
Registered: 11-2006
Posted From: 69.232.79.17


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Posted on Sunday, September 20, 2009 - 1:40 pm:   

Or you could check for the 12 volts with a 12 DC volt meter on each post until you find the right one.
Grant Thiessen (Busshawg)
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Username: Busshawg

Post Number: 221
Registered: 10-2007
Posted From: 206.45.93.160


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Posted on Monday, September 21, 2009 - 11:39 am:   

That's exactly what I did Roger, found it , works great
hojji firemaker (Hojjifiremaker)
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Username: Hojjifiremaker

Post Number: 32
Registered: 4-2008
Posted From: 67.142.162.35


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Posted on Monday, September 21, 2009 - 12:18 pm:   

cool. thanks guys! now I'll be rockin' down the freeway!
Tony LEE (T_lee)
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Post Number: 68
Registered: 11-2007
Posted From: 59.154.2.60

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Posted on Monday, September 28, 2009 - 3:29 pm:   

If you are going to be using the sound system a lot, it would be better to get a 24V to 12V converter rather than running it from just one battery. Dragging out of one battery of a series pair unbalances the system and makes it difficult to get them both equally charged.
Nellie Wilson (Vivianellie)
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Username: Vivianellie

Post Number: 319
Registered: 11-2008
Posted From: 75.178.92.43


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Posted on Wednesday, September 30, 2009 - 2:28 pm:   

Hi Grant-

Could you tell me which post that was? I was told there were actually two 12V posts but can't remember the numbers (I think one was #53?)

Tony: Would an equaliizer correct the uneven discharge problem? I've got one (a Vanner) but this guy in Vermont disconnected it... said it wasn't hooked up right. But then (of course) he left it disconnected.

I'd like to install my CB and a car type radio. And maybe some modest speakers... nothing drawing a lot of amps.

Thanks.

Nellie Wilson
marvin pack (Gomer)
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Username: Gomer

Post Number: 606
Registered: 3-2007
Posted From: 71.53.155.14


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Posted on Wednesday, September 30, 2009 - 9:33 pm:   

Nellie; Since yours is a 24 volt system. you can hook a wire on the positive terminalof the battery [where the battery has the ground terminal going to ground on the bus] and run the wire to the dash and hook your 12 volt stuff to it. I hope you understand what I mean???

Gomer
Nellie Wilson (Vivianellie)
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Username: Vivianellie

Post Number: 323
Registered: 11-2008
Posted From: 75.178.92.43


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Posted on Thursday, October 01, 2009 - 9:20 am:   

Marv, many thanks. I might try that - at least temporarily - but I recall an earlier thread (trying to find it) warning us away from that 'center post' solution (is that the same thing?). But can't remember why.

Nellie Wilson
Buswarrior (Buswarrior)
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Username: Buswarrior

Post Number: 1720
Registered: 12-2000
Posted From: 76.71.103.244


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Posted on Thursday, October 01, 2009 - 7:42 pm:   

Centre tapping a pair of 12 volt batteries in your 24 volt coach will imbalance the batteries.

If you steal some electrons from one, trouble is, you can't get them to go back. The charge has to go through both batteries, so to get the one topped up, you have to over fill the other.

This will shorten the life of the battery set, how short depends on how many electrons you regularly steal.

A popular solution is one of those lovely Vanner Equalizers. It equalizes the draw on the batteries via smarty pants technology. There's a post somewhere recently about them.

Available at the transit scrap yard near you.

Any transit with a 24 volt system will have one or two equalizers.

From a practical standpoint, go ahead and centre tap for the CB and a radio. If you are worried about it, throw a 12 volt charger onto the low side battery now and again until you find an equalizer.

happy coaching!
buswarrior
Rob Norgren (Robsedona)
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Username: Robsedona

Post Number: 131
Registered: 11-2007
Posted From: 75.210.57.235


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Posted on Thursday, October 01, 2009 - 9:51 pm:   

I did my Radio, CB and Ham from the house side so I could also use them when the bus is turned OFF
works for Me!

Rob

(Message edited by Robsedona on October 01, 2009)
hojji firemaker (Hojjifiremaker)
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Username: Hojjifiremaker

Post Number: 64
Registered: 4-2008
Posted From: 67.142.162.30


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Posted on Saturday, October 03, 2009 - 12:59 am:   

Nellie,
Inside the control panel outside of the driver's window, there is a box with a power amp on the inside of the door itself (on my 1989 102a3 anyways), and on the front side of it are plug-ins for the radio... I didn't see them before beginning this thread, but while looking around for the posts faster freddie was talking about, I found them.... They are not the posts he was referring to, at least I don't think so, but they say 'RADIO' (which is a pretty good indication!!!) and my multimeter says 12 volts!, so whew hew!!! It is a much shorter (and easier to hide) run for a wire from there than it is from the batteries... in addition to this, the big book confirms it.

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