Question about the Sun tach

[Car #4]

Can someone tell me which wire is the signal wire? Black is ground and white is the light. That leaves power and signal. Shouldn’t they both be insulated? Shouldn’t the signal wire be green?

 

[pnora]

Should be a green wire. Some one might of hacked in a makeshift harness. As I recall the harness plugged in the tachometer. Take it apart and see if there is a plug. If so I believe the letter is on each female pin hole. R-red[Keyed 12 volt hot],G-green[coil -],B-black[ground], W-white[light]

 

[Car #4]

Ha! Correction, bare is ground. So black must be the signal wire. Weird. You would think it would be standardized and everybody would use green.

 

[pnora]

Ha! Correction, bare is ground. So black must be the signal wire. Weird. You would think it would be standardized and everybody would use green.

Thats not the wires it was made with.

 

[Car #4]

Ya I’m starting to think the same. Don’t you love this game?

 

[Car #4]

Thanks @pnora

 

[Kobrak]

Just confirmation as I had just looked at my super tach II last night sitting in the trunk, it does have Red, Blue, Green and black.

 

[pnora]

Just confirmation as I had just looked at my super tach II last night sitting in the trunk, it does have Red, Blue, Green and black.

View attachment 1539413

View attachment 1539414

Right. But that plug was added by someone.

 

[kiwigtx]

Right. But that plug was added by someone.

That was a real hack job if ever I saw one.

I modified mine, but at least I maintained a colour strategy - 4-core flex because I had a roll, and it saved on wrapping outside the dash area.

 

[pnora]

That was a real hack job if ever I saw one.

I modified mine, but at least I maintained a colour strategy - 4-core flex because I had a roll, and it saved on wrapping outside the dash area.

A true hack cuts a Kiwi in half with a greasy hack saw.

 

[kiwigtx]

Just confirmation as I had just looked at my super tach II last night sitting in the trunk, it does have Red, Blue, Green and black.

Without looking at instructions...I would guess it to be;
Red - 12 Volts
Black - ground
Green - tach signal
Blue - light


Then I would test those cables and look inside for confirmation.

 

[kiwigtx]

A true hack cuts a Kiwi in half with a greasy hack saw.

Only if someone has already used the butter knife.

 

[pnora]

Step-by-Step Guide: Wiring Your Sun Super Tach II with Diagram Included

 

[pnora]

Right. But that plug was added by someone.

I am going to eat that statement. They must of had several wiring changes throughout the years. One of mine had a round hard connector with 4 female pins and it plugged directly to the circuit board. But here is another harness that matched the posters photo of his tachometer.

 

[Kobrak]

Thanks!!!

 

[Kobrak]

I am going to eat that statement. They must of had several wiring changes throughout the years. One of mine had a round hard connector with 4 female pins and it plugged directly to the circuit board. But here is another harness that matched the posters photo of his tachometer.

View attachment 1539440

What is interesting is I don't have a white wire, seems to be blue instead?

 

[Kobrak]

I am going to eat that statement. They must of had several wiring changes throughout the years. One of mine had a round hard connector with 4 female pins and it plugged directly to the circuit board. But here is another harness that matched the posters photo of his tachometer.

View attachment 1539440

Also, due to my ignorance, do you mean there is a place this things plugs into under the dash, or there is a board that is Sun Tach's that would be added somewhere under the dash?

 

[pnora]

What is interesting is I don't have a white wire, seems to be blue instead?

Who knows why. Common to be white. Maybe they ran out of white wire. Or being white all the time was racist? [lol]

 

[pnora]

Also, due to my ignorance, do you mean there is a place this things plugs into under the dash, or there is a board that is Sun Tach's that would be added somewhere under the dash?

No. There were some old tachometers that had a driver module that was wired in and then the tach was wired to the module. The later ones like yours has a disconnect plug but the ends are loose and need to be wired to the correct sources.