Blue Bird Ceiling Speaker Wiring

[SkyMaster]

Of the eight ceiling speakers only two are working. I pulled the radio plate in the dash as well as the plate with the light switch's in an attempt to locate the speaker wires. No joy.

From the back of the radio only one of the four speaker outputs is connected to the INT\EXT wiring harness.

I pulled the plastic cover encapsulating the main wiring harness that runs down the drives side of the bus.
The wiring from the speakers to the main harness looks great and the main harness looks factory and appears to have never been opened.

The main harness runs down the pillar right behind the drivers seat to the electrical panel under the drives side window.
I could not find any wires in the electrical panel or in the radio cavity that correspond in color of wires used to connect the speakers.

I have the service manual and have downloaded all the wiring schematics from the Blue Bird portal and cant find anything relating to the speakers, there is a diagram for the radio but it does not include speaker wiring.

Has anyone run into a similar issue or found a wiring diagram for the sound system?

 

[nikitis]

If you have 8 speakers it's likely in pairs and dividing 1 wire per 2 speakers. Decks typically have 4 speaker wire channels. Each one giving off anywhere from 30-55 watts per wire, when you pair them you divide the wattage in half per speaker.

Having only one wire plugged in for the speaker would make perfect sense as to why only 2 of your speakers are working. You need to find the end wires for the other 3 sets of 2 and plug them into the back of your deck.

 

[SkyMaster]

Hey Nik,

Thanks for the reply, I'm good with the final connection to the radio once i find the wires, but want to explore all avenues before opening the harness and manually tracing them.

 

[nikitis]

Gotcha, Yeah I'm at the stage where i'm searching for speakers to buy and a stereo head unit. Since my bus didn't come with anything including a factory harness to connect to, so I'll be wiring it 100% myself. Never done a stereo system, but researched the **** out of installation so I believe I understand everything it requires now. Just need to do it.

Pretty much needs a ACC to the head unit for power on key on, then 4 wires out to the speakers, 1 wire per speaker if using 4, 1 wire per 2 speakers if using 8, or if I decide to add an Amplifier, hook that straight to Bat+, and there's an extra wire from the amplifier that goes into the head unit telling the amp to only draw power when the head unit kicks on. So you tie it into the ACC wire of the head unit, then when the head unit powers on, the amplifier detects it and starts drawing power straight from the battery to give your speakers way more wattage per speaker, and that's pretty much it.

There's far more tweak settings like gains etc, but most of that is just adjustment of power to the speakers under the hood.

 

[SkyMaster]

Made some progress today. The eight speakers only use two channels from the receiver.

Four speaks running down the drivers side of the buss use one channel and the right side of the bus use the other.

The speaker wires are orange, blue w-black stripe, white w-green stripe, purple, and purple? (yes two purples) This is where the confusion starts...

The orange wire is the negative side on every speaker, however, there are no orange wires in the wiring harness leading to the receiver, WTF? (Thanks Blue Bird)

Somewhere in the harness the negative side changes color from orange to purple?

Also, these speakers are ran in series, so if one fails the rest fail. I tested the speakers individually and found five that were bad. With the two new speakers on hand in addition to the remaining working speakers I was able to test each side separately and both sides worked.

What a pain. A wiring diagram would have made this a simple and quick repair. New speakers ordered.

 

[nikitis]

Yikes, that's wattage divided by 4. You do not want that, I'd upgrade the head unit and do 2 more runs of wires to make it at least divided by 2. It will sound a lot louder and better if you do. Sounds like the head unit is garbage that was supplied by BB. The speakers may sound a lot better if you do this, you'll double the wattage they were getting.

Or you could keep the head unit and buy a 4 channel amp that could send the total wattage to each speaker they are capable of.

 

[SkyMaster]

The original head unit was worn out and the CD player was packed full of dust and dirt so I replaced it with a new Pioneer.

This design was clearly a cost cutting move by Blue Bird, as we know, running four channels to two speakers produces superior sound quality as opposed to two channels running four speakers.

I doubt the kids these busses were designed for would know the difference, or even care.

 

[Mr. Beefy]

This design was clearly a cost cutting move by Blue Bird, as we know, running four channels to two speakers produces superior sound quality as opposed to two channels running four speakers.

Your amplifier documentation (whether stand-alone, or the amplifier section of your head unit) will specify the range of speaker impedences it can drive per channel. That's the overarching determinate of how many speakers you can/should drive per channel (there are multiple factors to consider, but this is the 'big one'). So - strictly for purposes of example - if you have 2 8-ohm speakers, and your documentation states the amplifier expects 4-ohms impedence, you'd have to wire them in parallel (which would divide the impedence, making the circuit ~4 ohms). If you had two 2-ohm speakers, you'd have to wire them in series. Or, of course, a single 4-ohm speaker would work too.

There are actually quite a few factors you want to consider and balance with each other if you want a clean-sounding system, but the above forms the boundaries in which to consider those other elements. For example, you'll want to consider how your choices impact the wattage driving each speaker, along with the speaker's acceptable wattage range.

If keeping the stock components is a budget thing, I get it. But there's likely nothing optimal about anything in your stock system. The wiring is likely too thin to support any real power, the speaker locations are likely horrible for optimal sound imaging, and the speakers themselves are most likely garbage. It's possible to take a relatively cheap amp and pair it with a good set of speakers, driven in the upper-range of its impedence range, and get good sound quality (though probably not high SPL). But if your speakers are poor quality, no amount of money you throw at what's driving them will matter.

 

[nikitis]

Yeah this is partly why I'm Glad there wasn't any sound system in my bus to start with so I can just do it fresh, with the right AWG, amps, etc from the ground up rather than trying to reverse engineer what Blue Bird (Or Thomas in my case did).

Today is black friday though. Time to buy a sound system.

 

[SkyMaster]

The factory speaker wire is actually very stout, but this is just a basic system and I'm not expecting anything more than all the speakers to work. Not to mention the speakers were 18 years old, disintegrating, and at the end of there life, so anything will sound better.

If the head unit fails ill consider installing an amp and running new speaker wires.

I've built many high end mobile audio systems but this is just a rarely used vehicle and not a daily driver.

U.S Amps FTW

 

[Dragonpop]

When I did the sound system on my 96 Bluebird the original setup used 4 ohm speakers wired in series and I found that if you look closely at the wires you will find that they are both colored and numbered the numbering really helps in finding what is what. The numbers are quite visible once you see them and the whole bus is wired that way.

 

[SkyMaster]

Hi Dragon, I did notice that as part of my investigation, some of the wires had overspray on them and a few others were covered by wire loom. At the time it was easier to perform a continuity test to figure things out.

This was really an isolated incident as I couldn't find a wiring diagram for the speakers.

Update : all new speakers installed and everything is working as designed. Its nice to have a bit of music while you're working on the bus

 

[nikitis]

Congrats. Yeah I can't wait. My head unit came in the mail yesterday. Now gotta buy some speakers and wire it up myself. Bought an Alpine UTE-73BT. It's not fancy looking. Looks like an older traditional single din radio but does have bluetooth capability which is really all I wanted anyway. Any music I play now comes from my phone then via bluetooth to the car/bus.

 

[SkyMaster]

Congrats. Yeah I can't wait. My head unit came in the mail yesterday. Now gotta buy some speakers and wire it up myself. Bought an Alpine UTE-73BT. It's not fancy looking. Looks like an older traditional single din radio but does have bluetooth capability which is really all I wanted anyway. Any music I play now comes from my phone then via bluetooth to the car/bus.

Nice, keep us posted on the build