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Zumo/J&M 2003cb wiring question

exfed750

New member
I’m looking for help in wiring two audio inputs into my J&M 2003cb handlebar unit. A little background: my RT is wired with a Zumo 550, equipped with an XM radio puck pumping music into a wired headset coming from my J&M 2003cb handlebar unit. The Zumo has 3 different music choices; XM, books, and recorded music on a memory card. The Zumo passes all audio out via a mini stereo plug on the bike mount. J&M has a mini male plug that connects to the unit via a modified 3 pin connection, and volume of the output is controlled via a rotary knob on the top of the control head. The Zumo has Bluetooth capability for phones and headsets, however, it does not pass XM audio via Bluetooth. To connect a phone through the Zumo and the J&M, it was necessary to purchase a Bluetooth adapter and a wiring cable to connect it to the control head. That cable connected the audio from the Bluetooth via a 3 pin connector (you have to disconnect the one from the Zumo (XM/audio)) and connect the new Bluetooth unit. Here’s the question I have (J&M was unable to answer this):

If I make a “Y” three pin cable to connect: 1) the original XM/Zumo 3 pin output & 2) the three pin Bluetooth unit output, is diode(s) needed to prevent the output of either unit flooding back and possibly causing damage to either? I suspect that the output of both cable is an AC audio signal similar to a wired telephone (DC voltage powering the line and an AC audio signal superimposed on the top.)
(I’m hoping someone with some electronics training, or experience with this can keep me from screwing up some very expensive electronics , and keep me happily cruising down the road, with music and my phone )
A Basic diagram of what I’m trying to determine is below:
 

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Sorry, I'm in a bit of a hurry and I've not read your post completely (my head is mush currently so much of it wouldn't sink in anyway). ;-)

However, if you want to move away from fully wired, I did that about 5-years ago using the Sena SR10 to cut the umbilical cord between my Autocomm comms system, CB, Nav, and helmet unit. I don't use it anymore (just collecting dust, but it worked well until I went fully Bluetooth.

Sena Product pages:
https://www.sena.com/product/sr10-sr10i/faq
http://www.buysena.com/sr10-10.html?sc=24&category=4481

Overview: https://www.webbikeworld.com/sena-sr10/
 
I have looked at the Shorai batteries and they are pricey. I keep going back to the Westco I get from BeemerBoneYard for $80. They last three years sometimes more. At that price, I am paying the same as a Shorai and its a fresh battery. Just my $0.02 ...
 
Without knowing the actual specs of any of these devices, let me add a caution that any time additional devices are wired in parallel (as with the Y adapter), more current is drawn from the source.
The source may not be designed to be able to provide that extra current, so its output stage may heat up and eventually fail.
The actual current will depend on the resistance (DC) and/or impedance (AC) of the two loads; lower resistance increases the current drawn. (Example: two units that have identical resistance, wired in parallel, pulls twice the current.) If both units have a very high input resistance, that may not be an issue, but if either one is "low", it could be.
I have no idea if crosstalk between the two would happen.
 
For what it is worth, I have the JM CB and helped install one an a friend's BMW. The plug is just a typical stereo input, common, right and left. That said i would not try just wire two inputs together. Find some sort of two into one combiner, isolator. I know someone makes, or used to make one. I looked at Sierra Electronics and didn't see anything, but might have missed it.
 

I don't think this is what he needs.

I remember there being a device available to run two outputs into one input, plus the on output would over ride the other. In this case music would be over ridden by the GPS. If you just run the two together with a couple ground loop isolaters, if it works the music will be playing with the GPS talking at the same time, probably just hear gibberish, or what ever your two outputs are.
 
2 of those paralled will do the same thing

??
The device I mention will shut off the audio from one source, you pick which one, when the other audio is active. In other words, play music constantly, but get random commands from a GPS the will kill the music for the short time the GPS is talking.

If you just wire them together both will be sending audio at the same time, two people talking at once. That doesn't work for most people.
 
??
The device I mention will shut off the audio from one source, you pick which one, when the other audio is active. In other words, play music constantly, but get random commands from a GPS the will kill the music for the short time the GPS is talking.

If you just wire them together both will be sending audio at the same time, two people talking at once. That doesn't work for most people.


The old Autocom systems did that. If one wants priority options.

IIRC the Mixit did that http://www.mixitproducts.com/
 
Eureka! Chicken teeth!

I think that I may have found a solution. Thank you all for your comments, I may be back if it doesn’t, but here is what I’ve found. Waaaay back in 2007, when the Zumo 550 was all the rage, J&M manufactured an adapter cable specifically for the Zumo 550. It’s identifier is a CFRG-Zumo550 and it allows you to connect the mini stereo output and micro mono input to the mount used by Garmin on the 450 and 550 models. Since the Zumo is Bluetooth capable, you can pair it with your phone, the caller comes into the headset and the audio from your helmet mic goes back to the caller and the Zumo. I found it in a company catalog from 2007, and back then it was $329! It is now on close out on eBay for much less. So if this works, I may have a J&M IPBT unit for sale. I’m surprised that no one at J&M thought of this, but I guess I didn’t ask whether or not they had a workable item in the past.
Once again, thanks all for helping me try to solve this Rubick’s cube
 
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