Tach ground

[czakky]

Slightly annoying problem with my tach as it flutters a little, not a huge deal but figure i should take care of it if/when I can.

 

On Carl Allison's awesome wiring diagram it shows two grounds for the tach and a 1 way AMP? connector. Where are these typically? I can't recall seeing a single connector like that. I hjave looked for the grounds to no avail....

 

 

[docc]

One ground is the bulb socket for the illumination. They are certainly known to get loose and can be secured with JB Weld or the likes while leaving enough contact area for a ground path.

 

The other ground must be for the tach function, but doesn't show a wire. I would assume it also grounds, then, through the case and mounting fasteners. I'm thinking that single pole AMP connector is under the relay block at the back of the wiring harness.

[czakky]

Awesome. Never had the unit apart guess I figured it was in the loom. Thanks docc!

[docc]

Hubert (luhbo) seems to know these tachs pretty well. Perhaps he'll chime in (?)

 

Kiwi_Roy, too . . .

[luhbo]

Yes, had open one or two of them. As docc said, the housing ground connector is for the bulb only. The electronic's ground comes with the harness, but I didn't check from where this 3-wire harness comes. The single pole AMP leads the signal pulses, so you might check where this cable leaves the harness and trace down the ground from there.

 

Hubert

[czakky]

Looks like i will be hunting this down next time i have my tank off.

 

Do you think a shaky needle like this might be a mechanical issue with the tach itself? Or would a weak ground/connection contribute?

[luhbo]

Could be both. First define 'shaky'. Next thing is that in these tachs Veglia had money for one coil only. This coil works against a simple spring. So, while damping is marginal, a little shakiness can also be just normal (for this type of instrument).

A bad ground of course could also be the reason, as well as a dying coil.

 

Hubert

[czakky]

It was butter smooth now it shakes a little nothing major. Gets worse as revs climb.

Ive got a little more to go on now. Thanks Hubert

[luhbo]

Is it a Veglia unit or does your bike already have the ITIs? I don't know their internals, they could be completely different. I still should have a picture of an opened Veglia, somewhere, means I'll post it once I found it.

 

Hubert

[AndyH]

My fourth tach (Veglia) has just packed in. This bike serially destroys them! I've had one repaired by Casa di Moto and the other by Peter Bond in the UK. The Casa di Moto fix was the best, for a short while at least! But they all seem to go that way eventually.

 

Could this be a grounding problem?

 

I'm not going to bother paying to get another one fixed again if the cause is an electrical fault outside the tach itself that's just going continue wrecking them! That issue'll need sorting first.

[werks]

^ very wise.