Tach Install Question

[CHEVY5637]

I have a 2006 softail fxsti. Wired up everything except stuck on the last wire which is supposed to hook up to the negative side of the coil. I have four wires in a plug that connects to the coil. Yellow with green stripe Gray with black stripe Yellow with blue stripe and Blue with pink stripe. Does anybody know which wire I should be tapping into? Thanks in advance.

 

[Chopper]

Don't know if this will help? Here what the wires are for.

 

[PigSnot]

Just trying to help as I just installed the mini tach on my 07 FLHR and I may be missing the point totally:
Is your last wire you're referring to the pink, the tach signal wire? Looking at the instructions -J03119 that came with my unit, does your 06 FXSTI not fall under ‘For all other models’ as per last paragraph on pg 3 of 8, and connect to cavity 3 of connector #39B, the speedometer plug? Seems to me that is the only place your 06 softail fits the install instructions, same as my 07 RK.

 

[Hoople]

Does anybody know which wire I should be tapping into?

Maybe none. Was the tach your installing made for twin coils that are single fired?
There are 2 "negative side of the coil" wires on the diagram Chopper uploaded. Y/BE & BE/O are BOTH negative sides of the coil. One is for the front coil and the other is for the rear coil. Even though the coil is a single unit, it actually is 2 coils each having a negative side of the coil. Be careful, there are ~ 300 volt spikes on those 2 wires.

Your tach will display either the correct RPM or 1/2 the correct RPM. It all depends on the tach your installing.

Hard to answer your question since you gave us no info on what your installing.

 

[CHEVY5637]

Thanks for all your replies. It was a tach from JP Cycles which stated it would work with my year of bike. The instructions it came with were for an older style bike. It was a green wire from the tach that connected to negative terminal on coil. Luckily I called a friend who knows a friend that answered my question. Thanks again and Hoople is right.

 

[Jack Klarich]

Thanks for all your replies. It was a tach from JP Cycles which stated it would work with my year of bike. The instructions it came with were for an older style bike. It was a green wire from the tach that connected to negative terminal on coil. Luckily I called a friend who knows a friend that answered my question. Thanks again and Hoople is right.

Hoople is always right when it comes to electrical:s