Originally Posted by BrAinZ
Thanks for the brilliant advice, I really appreciate it.
I guess there isn't a specific lead to go from the Yamaha hub to the Garmin network?
So would I need a Garmin T connector and a Garmin "drop cable" ?
Looking at eBay, something like 351068926958?
I think I have normal Command Link gauges, not the plus ones.
Yes, it looks as if you do have the normal command link. I think that the plus ones have a full LCD colour display.
In order to modify the existing network to be "correct" you don't need any bits.
From what I have read the standard Command Link network works using NMEA 2000 protocols (ie it talks in that language). So all you need to do to make the two networks talk to each other is to physically connect them together.
At first I wrote this post agreeing with you that you would need another "t" connector, then I realised you wouldn't, then I thought you would, and finally I decided that you wouldn't! I will explain why below, it means that my last post is actually slightly wrong. All you need to do is get a drop cable like you say and hack it up following the guide here: El-cheapo Yamaha command link to Garmin NMEA 2000 cable works - The Hull Truth - Boating and Fishing Forum
I actually have one of those 6ft drop cables I was about to put on ebay right now, you're welcome to it for £12 inc postage (99p saving off that link
The link above seems fairly self explanatory, and it will be easier for you as you are using genuine cable. Having looked at the link in detail, as I mentioned above, it actually makes my last post somewhat incorrect.
To put it simply: the way that we are connecting the networks is such that the existing networks are being joined...we aren't just adding the engine to the NMEA2000 network. As a result there is no need for another "t" since the command link hub is just becoming part of the daisy chain of connectors. So, assuming that you have set up the existing NMEA2000 network on the boat like I have suggested, all you need to do is remove one of the terminators from either the top or bottom of the daisy chain and plug your new cable into there. In making the new cable you will have by necessity removed one of the terminators from the command link hub, so you can see that there are two terminators remaining...one on the hub, and one on the "t" connector line. It is obviously important that you only connect the two wires (pins 4&5) and not 2 or 3, because that would end up with two power supplies to the network which is not good.
I think that explains it...? Basically just follow the explanation in the thread I have linked to, drilling out the command link terminator and wiring Pins 4 and 5 from the Garmin drop cable to the connectors left in the plug by the removal of the terminator.
If this doesn't make sense then please do say! Like I said earlier today, the beauty in this NMEA 2000 stuff is that it is all so simple as it means everything just connects to everything with one wire...but it is far to easy to make things seem too complicated!
Looking again at the picture that I put the red rectangle I am slightly confused why there are wires coming out of all the plugs visible. Could you post a pic of that box direct on if possible?
(Scroll down in the link above to see the pin out diagrams that I refer to)