The tach is backlit, I literally spliced directly into the Road King Speedometer wires....

 

 

I haven't completed all of the mods I'm making (adding Road Glide Fairing to front, radio controls, etc.), so as of right now I have I have stripped, twisted, and taped the connections - I make more permanent connections later, but this "works" until then.

 

Thanks to Max Headflow and riotron for all their help.
I got a police tach on ebay for 25 bucks
Bought a 2017 rk speedometer turn signal cluster harness and took the 12 pin deutch connector with the 4 wires (Red/Orange stripe- POWER, Black/Green stripe- GROUND, White/Black stripe- CAN BUS LOW, White/Red stripe- CAN BUS HIGH) and cut it out of the used harness. 3/8 shrink tubing over the wires
Wired the 4 wires to the same 4 wires underneath the fuel tank console.
Bought a 5 inch tach cup from issprogauges and 2 "L" brackets from home depot, grommetsfrom autozone to mount the tach and.... DONE!
Finally.
Here's a picture:


5 inch police tach

 

yeah, but can you see it?

looks good, thanks for sharing how you got it done

 

 

Looks great! My bike is close to done, but need another couple weeks for sorting out odds & ends. Doing breather by-pass, V&H 4" exhaust, forward controls, and the previously mentioned Road Glide Front Fairing - still trying to sort out the oil pressure gauge, but I see there are a number of threads on that to research....

 

Finally got it right with no errors:
See: 18 Road King and the tach **** post

 

Hello Max; I am wanting to add a bar-mounted tach to my 2016 Road King, and came across this thread you are involved in. Based on your experience, and my inability to find a definitive answer anywhere else, could you answer a couple of questions for me?
1. Can or Can't a regular analog tach be connected to the negative side of a coil on these bikes, without causing a computer issue from the CAN-BUS system? It seems to me the connection at the coil is just a dumb voltage signal with no feedback to the computer from the tachometer....
2. I'm looking at the Speed Hut CAN-BUS tachs, but you seemed to indicate a problem with compatibility between the tach and Harley CAN-BUS system.. Seems maybe not so plug-and-play..?