Old Tachometer

[Paulywog0667]

I read tachometers with a light have a ground. The light wire is red/grn/wht. Before risking taking the cover off. Is the ground homemade to one of the studs that holds the tach in place?

 

[GA_Boater]

All tachs have a ground or the tach won't work. Ground, 12 volts and signal are needed. A light shares the ground. Did one of the studs have a ground attached?

Does the tach work and the light doesn't? Burned out bulb, maybe?

 

[Paulywog0667]

No ground, only the loose light wire. Would I run that to ground for the unit or splice an extra to the tach housing bracket?

 

[Paulywog0667]

Or did you mean the light housing touching the tachometer housing shares a ground to the bracket and ground there? The light might have jumped over from the hours meter.

 

[GA_Boater]

Does the tach work as currently wired?

 

[Paulywog0667]

Does the tach work as currently wired?

I had the red and signal hooked up. Getting a tach reading, but don't know if it's accurate if supposed to be grounded. The light wire is not connected.

 

[GA_Boater]

With no ground the tach won't work at all. You must have a ground hooked up somehow.

Are you trying to get the light to work? Connect the wire to the wire for the light for what ever lighted gauge is next to it.

 

[Paulywog0667]

The light isn't working, but 12v to red and signal to gray gave a tach reading. Unless it grounds itself, idk.