V-Twin Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
103 Posts
Discussion Starter #1
I recently bought a 4 wire tach for my softail standard FI. No problem getting juice to it with backlight and power wires spliced together and hooked into headlight fuse. Ground wire was no problem either. However having heck of a time with proper connection of the 4th wire to coil. We tried putting the wire from the tach for the coil directly into end of the plug wire connection to the coil, and reattaching plug wire to coil. Figured it was making contact in there and should work. Wrong. We ended up with one cylinder not firing. Tach is lit up and kinda works but jumps all over the place so something is not right. Somehow it is messing up the plug we have it halfway connected to. Anybody have any thoughts on how we can connect this wire to coil better and avoid this problem? Thanks
 

·
Registered
Joined
·
3 Posts
There is a tach. wire under your dash. A service manual should help on wich wire it is. You shouldn't have to wire it to to coil.
 

·
Registered
Joined
·
250 Posts
Is it carb or EFI? If EFI, the ECM module has a tach output pin. It is a pink wire and goes to the tach as the tach signal input. Not all aftermarket tachs will be able to correctly interpret the voltage/phase signal on the pink wire and thus they won't work on EFI bikes.
 

·
Registered
Joined
·
1,496 Posts
pelicansoftail said:
[
We tried putting the wire from the tach for the coil directly into end of the plug wire connection to the coil, and reattaching plug wire to coil


So your tach can handle 28,000 volts ??

You need the triger lead to the coil, there are just two wires (other than the plug wires)so not hard to figer out.

I feal the tach my be blown but you never know...
 

·
Registered
Joined
·
103 Posts
Discussion Starter #6
I was able to locate the pink wire in the dash per jv2000wg and connected to that. Tach appeared to work and idled right at 1000 rpm. However when I actually took the bike for a spin around the block it jumped all over the place. I am guessing this one is not made for EFI bikes as Tsuter says. I need to take bike in for the first 1000 mile check and will just have them put on the HD tach then. Thanks for everybodie's input. You win some-lose some.
 

·
Registered
Joined
·
224 Posts
Don't make any difference if carb or EFI, use pink wire. Like Kags said if you hooked to a plug wire you FRIED your tach.
 

·
IronButt
Joined
·
6,364 Posts
There is a TSB on tach probelms . One thing is wire routing it can pick up other electrical interferance and cause tach to jump around. But hooking it to the plug wire I would guess you are in need of a new tach. take a look at the Auto metter ones. I don't care for the poor action quality of the HD tach.
 

·
Registered
Joined
·
6 Posts
I tried the Autometer tach on my Deuce. Besides dealers not knowing if the bike is single or dual fire, how to wire it and a lot of other confusion, I gave up and ordered a Harley tach. At least more people have hooked this style up. Good luck. Gordy
 

·
Registered
Joined
·
561 Posts
My neighbor has a non Harley tach and it jumps around everywhere off idle. I spent the $ and installed the Harley tach-- works great-- idles at 950 when warm, very slight jumping at higher rpm's (barely noticable). Yes-- Pink wire is correct, you can pluck it out of the harness right under the tank. (if you are comfortable in doing so). Maybe Autometer makes it for H-D?

If you got the tach to read steady idle after pink wire hook up, it may not be fried-- the jumpiness could be the tach itself.

Just my 2 cents...
 

·
IronButt
Joined
·
6,364 Posts
You know a dealer that can not hook a tach up?? I find that hard to believe as a dealer tech we have been gettting TSB's on the tach problems for a wheil now. All of which tell you how and where to route wires and the problems that are occuring. As for NON HD stuff let's get real most of the HD stuff is made over sea's and has the price jacked up. All the chrome stuff has made in taiwan stuck to it. I know that automoter tach work as for other I have not tried them. The SE tach that HD sells are autometer.

And the pink wire is under the dash panel on most bikes. Make to sure to route it away from other wires in the bundle. Good luck
 
1 - 11 of 11 Posts
Top