Gauges driving me nuts

[barberman91]

The wire goes into this 4 wire connector. The other half leads to an eyelet that grounds to the bottom of the coil.

[FJ_Hooligan]

Is that wire stuck into the same slot as the red wire?  If so, then it appears that you're grounding a main lead to ground which will pop any fuse you install. 

Maybe the PO used it to tap off of a power source.  Using a black wire as a power wire is dumb.

Ohm the other wire to ground.  I'll bet you see 0 ohms

[barberman91]

Yep, you are right. I wonder what the ground wire was supposed to be hooked to?

[FJ_Hooligan]

Looks like he had some accessory wired in there but removed it before selling the bike.  There is 12V switched power and a ground.  I guess all he had was black wire.

If you're not going to use the power wire, wrap it in something to prevent it from grounding on something.

[barberman91]

Hmm. What a let down. I was hoping it was going to be an easy fix for my tach

[barberman91]

 I cleaned every connection and used dielectric grease on all of them. When I hook the cluster up I notice the tach bouncing ever so slightly at zero. I'm starting to think it's a cluster issue.

[barberman91]

Is there a certain way to test the wiring to the tach with a multi meter?

[FJ_Hooligan]

Find a ground point on the gauge cluster or wiring as close to the cluster as possible and run a separate ground wire from there directly back to the battery.

[ct7088]

The gray wire at the tach and the gray wire from the igniter from the 4 pin connector are spliced either at the 17 pin connector or close to it. The motor runs so you know that the connection from the coil to the igniter is good. There should be voltage on the gray tach wire when cranking the motor or when running. The igniter grounds the primary winding causing the coil to fire in response to the pickup coil. Do you have a dwell meter?

[wco56]

I know this is an old thread, but did you ever find a way to static test that tach? I have checked continuity all the way up to the dash on mine and everything looks good. I got a used dash that the owner said the tach worked in and N/G. Did the separate ground on both dash units, still no good. Have not really seen a detailed testing method for the unit itself.

[Pat Conlon]

Did you ohm check (not just continuity) the gray signal wire from the #1/4 coil (right side) to your tach?

[wco56]

Pat, Thank you for responding to me. What I did check was the pulses with my VOM set for AC and all was good. I did not check ohms from the coil up to the dash, but I did come up with a solution. I cleaned all the connections on my original dash without success, but I had better luck when I did the same with the replacement dash. That tachometer worked when plugged into the harness so I just swapped them out and I am now in business. The tach with 5000 miles use I am assuming is no good, but the one with ten times that is working. I guess it's a bit like exercise...use it or lose it. Thanks for connecting on it.
Wayne