Splitting one nmea2k data cable into two?

I don't want to use a t-connector because of the shape.

I have a few wires coming thru-hull to my mast. I've added a few holes to accommodate and I'd like to just splice a single multi-wire data cable and have a single hole rather than three. Yes, I know there will be a wider diameter.

Can a canbus data cable just be split or is there something internal to the t-connector that allows the splitting beyond just a regular splice?
 

aremmes

Member
65
29
Reading, PA
You can cut the cable and splice it with field-installable connectors, although a bulkhead connector seems like a better fit for your needs. Either way, there's nothing special to the cable or the T-connectors -- the former are wired straight thru and the latter are electrically similar to vampire taps. The real magic lies in the transceivers in each device and the resistors in the terminators.
 

SimonGH

Member
446
106
Westbrook CT
I'm totally confused on what you're trying to do.

How many N2k wires do you have that need to go from the inside to the outside of the boat?

Are you trying to combine say 3 different lines into one pass through, then back into 3 lines?

While theoretically you can connect them all day long in any arrangement you want (as long as both ends have a termination), the network traffic starts to degrade and it can cause weird issues and errors.

A diagram of what you're trying to achieve would be very useful...
 
I think some more information may be helpful.
But, I will explain where I may have done something similar on my boat.

My cockpit instruments are mounted in a pod, on my deck, just above my companion way entrance.
My boat has a headliner inside.

The wiring to the pod runs forward to the head, which is beside the mast, then enters the space between the deck and the headliner and runs back to the pod. My problem was that the N2k connectors wouldn't physically fit between them. I looked at the field ends, but they were enough larger than the moulded ends to cause fitment issues inside my gage pod.

I cut a single N2k molded cable in half and fished it from each end. So the 2 cut ends met near my mast where the wiring to the mast is located. I installed a terminal strip, the same as the wiring to my mast is terminated, to make the terminations simple and connected the 2 wires together. You need to make sure that you also connect the shields, not just the wires inside. This has been working without issue on my boat for more than 5 years at this point.

You should be able to connect multiple cables the same way. It may not be the recommended way, but if the area is dry, clean, and away from other electrical devices that may cause noise, I believe you will be fine.
 
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